* [PATCH 4/4] posix-cpu-timers: posix-cpu-timers.c renamed to posix-task-timers.c
2010-07-30 9:57 ` [PATCH 3/4] posix-cpu-timers: Wider access to the thread clocks Tomasz Buchert
@ 2010-07-30 9:57 ` Tomasz Buchert
0 siblings, 0 replies; 11+ messages in thread
From: Tomasz Buchert @ 2010-07-30 9:57 UTC (permalink / raw)
To: linux-kernel, Daniel Walker, Stanislaw Gruszka, Peter Zijlstra
Cc: Tomasz Buchert
This rename reflects the fact that posix-cpu-timers.c contains
both CPU clock implementation and wall clock implementation.
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
---
kernel/Makefile | 2 +-
kernel/posix-cpu-timers.c | 1852 --------------------------------------------
kernel/posix-task-timers.c | 1852 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1853 insertions(+), 1853 deletions(-)
delete mode 100644 kernel/posix-cpu-timers.c
create mode 100644 kernel/posix-task-timers.c
diff --git a/kernel/Makefile b/kernel/Makefile
index 057472f..21e5fe8 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -7,7 +7,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \
sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o extable.o params.o posix-timers.o \
- kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
+ kthread.o wait.o kfifo.o sys_ni.o posix-task-timers.o mutex.o \
hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \
async.o range.o
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
deleted file mode 100644
index 04f49ce..0000000
--- a/kernel/posix-cpu-timers.c
+++ /dev/null
@@ -1,1852 +0,0 @@
-/*
- * Implement CPU time clocks for the POSIX clock interface.
- */
-
-#include <linux/sched.h>
-#include <linux/posix-timers.h>
-#include <linux/errno.h>
-#include <linux/math64.h>
-#include <asm/uaccess.h>
-#include <linux/kernel_stat.h>
-#include <trace/events/timer.h>
-
-/*
- * Called after updating RLIMIT_CPU to run cpu timer and update
- * tsk->signal->cputime_expires expiration cache if necessary. Needs
- * siglock protection since other code may update expiration cache as
- * well.
- */
-void update_rlimit_cpu(unsigned long rlim_new)
-{
- cputime_t cputime = secs_to_cputime(rlim_new);
-
- spin_lock_irq(¤t->sighand->siglock);
- set_process_cpu_timer(current, POSIX_CLOCK_PROF, &cputime, NULL);
- spin_unlock_irq(¤t->sighand->siglock);
-}
-
-/* RCU lock needed */
-static int thread_clock_allowed(struct task_struct *p)
-{
- const struct cred *cred, *pcred;
-
- if (unlikely(capable(CAP_SYS_ADMIN)))
- return 1;
- cred = current_cred();
- pcred = __task_cred(p);
-
- return (cred->euid == pcred->euid ||
- cred->euid == pcred->uid);
-}
-
-/* RCU read lock needed */
-static inline int process_clock_allowed(struct task_struct *p)
-{
- return thread_group_leader(p);
-}
-
-static int check_task_clock(const clockid_t which_clock)
-{
- int error = 0;
- struct task_struct *p;
- const pid_t pid = POSIX_CLOCK_PID(which_clock);
-
- if (pid == 0)
- return 0;
-
- rcu_read_lock();
- p = find_task_by_vpid(pid);
- if (!p || !(POSIX_CLOCK_PERTHREAD(which_clock) ?
- thread_clock_allowed(p) : process_clock_allowed(p))) {
- error = -EINVAL;
- }
- rcu_read_unlock();
-
- return error;
-}
-
-static inline int check_cpu_clock(const clockid_t which_clock)
-{
- return !IS_CPU_CLOCK(which_clock) ?
- -EINVAL : check_task_clock(which_clock);
-}
-
-static inline int check_wall_clock(const clockid_t which_clock)
-{
- return !IS_WALL_CLOCK(which_clock) ?
- -EINVAL : check_task_clock(which_clock);
-}
-
-/* Wall time clocks */
-
-/* Get the start time of the process/thread referenced by the wall clock.
- * RCU lock required. */
-
-static int get_start_time(clockid_t which_clock, struct timespec *start)
-{
- struct task_struct *p =
- find_task_by_vpid(POSIX_CLOCK_PID(which_clock));
- if (p && (
- (POSIX_CLOCK_PERTHREAD(which_clock) &&
- thread_clock_allowed(p)) ||
- (!POSIX_CLOCK_PERTHREAD(which_clock) &&
- process_clock_allowed(p) && p->sighand))) {
- *start = p->start_time;
- return 0;
- }
- return -EINVAL;
-}
-
-/* monotonic clock is used to get start_time and uptime
- * so the precision is twice the precision of the monotonic clock */
-
-int wall_clock_getres(clockid_t which_clock, struct timespec *tp)
-{
- int error = check_wall_clock(which_clock);
- if (error)
- return error;
- error = hrtimer_get_res(CLOCK_MONOTONIC, tp);
- if (error)
- return error;
- *tp = timespec_add_safe(*tp, *tp);
- return 0;
-}
-
-int wall_clock_get(clockid_t which_clock, struct timespec *tp)
-{
- struct timespec uptime, start;
- int error = -EINVAL;
-
- if (!IS_WALL_CLOCK(which_clock))
- return error;
-
- if (POSIX_CLOCK_PID(which_clock) == 0) {
- start = (POSIX_CLOCK_PERTHREAD(which_clock) ?
- current : current->group_leader)->start_time;
- error = 0;
- } else {
- rcu_read_lock();
- error = get_start_time(which_clock, &start);
- rcu_read_unlock();
- }
-
- if (error)
- return error;
-
- do_posix_clock_monotonic_gettime(&uptime);
- *tp = timespec_sub(uptime, start);
-
- return 0;
-}
-
-int wall_clock_set(const clockid_t which_clock,
- struct timespec *tp)
-{
- return check_wall_clock(which_clock) ?: -EPERM;
-}
-
-int wall_nsleep(const clockid_t which_clock, int flags,
- struct timespec *tsave, struct timespec __user *rmtp)
-{
- if (!IS_WALL_CLOCK(which_clock))
- return -EINVAL;
-
- if (flags & TIMER_ABSTIME) {
- int error;
- struct timespec start;
-
- rcu_read_lock();
- error = get_start_time(which_clock, &start);
- rcu_read_unlock();
-
- if (error)
- return error;
- *tsave = timespec_add_safe(*tsave, start);
- }
- return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
- HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
- CLOCK_MONOTONIC);
-}
-
-long wall_nsleep_restart(struct restart_block *restart_block)
-{
- return -EINVAL;
-}
-
-int wall_timer_get(struct k_itimer *timr,
- struct itimerspec *cur_setting)
-{
- return -EINVAL;
-}
-
-int wall_timer_create(struct k_itimer *new_timer)
-{
- return -EINVAL;
-}
-
-int wall_timer_set(struct k_itimer *timr, int flags,
- struct itimerspec *new_setting,
- struct itimerspec *old_setting)
-{
- return -EINVAL;
-}
-
-int wall_timer_del(struct k_itimer *timer)
-{
- return -EINVAL;
-}
-
-#define PROCESS_WALLCLOCK MAKE_PROCESS_WALLCLOCK(0)
-#define THREAD_WALLCLOCK MAKE_THREAD_WALLCLOCK(0)
-
-static int process_wall_getres(const clockid_t which_clock,
- struct timespec *tp)
-{
- return wall_clock_getres(PROCESS_WALLCLOCK, tp);
-}
-static int process_wall_get(const clockid_t which_clock, struct timespec *tp)
-{
- return wall_clock_get(PROCESS_WALLCLOCK, tp);
-}
-static int process_wall_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp,
- struct timespec __user *rmtp)
-{
- return wall_nsleep(PROCESS_WALLCLOCK, flags, rqtp, rmtp);
-}
-static long process_wall_nsleep_restart(struct restart_block *restart_block)
-{
- return -EINVAL;
-}
-static int thread_wall_getres(const clockid_t which_clock,
- struct timespec *tp)
-{
- return wall_clock_getres(THREAD_WALLCLOCK, tp);
-}
-static int thread_wall_get(const clockid_t which_clock, struct timespec *tp)
-{
- return wall_clock_get(THREAD_WALLCLOCK, tp);
-}
-static int thread_wall_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp,
- struct timespec __user *rmtp)
-{
- return wall_nsleep(THREAD_WALLCLOCK, flags, rqtp, rmtp);
-}
-static long thread_wall_nsleep_restart(struct restart_block *restart_block)
-{
- return -EINVAL;
-}
-
-/* CPU time clocks */
-
-static inline union cpu_time_count
-timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
-{
- union cpu_time_count ret;
- ret.sched = 0; /* high half always zero when .cpu used */
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
- ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
- } else {
- ret.cpu = timespec_to_cputime(tp);
- }
- return ret;
-}
-
-static void sample_to_timespec(const clockid_t which_clock,
- union cpu_time_count cpu,
- struct timespec *tp)
-{
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED)
- *tp = ns_to_timespec(cpu.sched);
- else
- cputime_to_timespec(cpu.cpu, tp);
-}
-
-static inline int cpu_time_before(const clockid_t which_clock,
- union cpu_time_count now,
- union cpu_time_count then)
-{
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
- return now.sched < then.sched;
- } else {
- return cputime_lt(now.cpu, then.cpu);
- }
-}
-static inline void cpu_time_add(const clockid_t which_clock,
- union cpu_time_count *acc,
- union cpu_time_count val)
-{
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
- acc->sched += val.sched;
- } else {
- acc->cpu = cputime_add(acc->cpu, val.cpu);
- }
-}
-static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
- union cpu_time_count a,
- union cpu_time_count b)
-{
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
- a.sched -= b.sched;
- } else {
- a.cpu = cputime_sub(a.cpu, b.cpu);
- }
- return a;
-}
-
-/*
- * Divide and limit the result to res >= 1
- *
- * This is necessary to prevent signal delivery starvation, when the result of
- * the division would be rounded down to 0.
- */
-static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
-{
- cputime_t res = cputime_div(time, div);
-
- return max_t(cputime_t, res, 1);
-}
-
-/*
- * Update expiry time from increment, and increase overrun count,
- * given the current clock sample.
- */
-static void bump_cpu_timer(struct k_itimer *timer,
- union cpu_time_count now)
-{
- int i;
-
- if (timer->it.cpu.incr.sched == 0)
- return;
-
- if (POSIX_CLOCK_WHICH(timer->it_clock) == POSIX_CLOCK_SCHED) {
- unsigned long long delta, incr;
-
- if (now.sched < timer->it.cpu.expires.sched)
- return;
- incr = timer->it.cpu.incr.sched;
- delta = now.sched + incr - timer->it.cpu.expires.sched;
- /* Don't use (incr*2 < delta), incr*2 might overflow. */
- for (i = 0; incr < delta - incr; i++)
- incr = incr << 1;
- for (; i >= 0; incr >>= 1, i--) {
- if (delta < incr)
- continue;
- timer->it.cpu.expires.sched += incr;
- timer->it_overrun += 1 << i;
- delta -= incr;
- }
- } else {
- cputime_t delta, incr;
-
- if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
- return;
- incr = timer->it.cpu.incr.cpu;
- delta = cputime_sub(cputime_add(now.cpu, incr),
- timer->it.cpu.expires.cpu);
- /* Don't use (incr*2 < delta), incr*2 might overflow. */
- for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
- incr = cputime_add(incr, incr);
- for (; i >= 0; incr = cputime_halve(incr), i--) {
- if (cputime_lt(delta, incr))
- continue;
- timer->it.cpu.expires.cpu =
- cputime_add(timer->it.cpu.expires.cpu, incr);
- timer->it_overrun += 1 << i;
- delta = cputime_sub(delta, incr);
- }
- }
-}
-
-static inline cputime_t prof_ticks(struct task_struct *p)
-{
- return cputime_add(p->utime, p->stime);
-}
-static inline cputime_t virt_ticks(struct task_struct *p)
-{
- return p->utime;
-}
-
-int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
-{
- int error = check_cpu_clock(which_clock);
- if (!error) {
- tp->tv_sec = 0;
- tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
- if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
- /*
- * If sched_clock is using a cycle counter, we
- * don't have any idea of its true resolution
- * exported, but it is much more than 1s/HZ.
- */
- tp->tv_nsec = 1;
- }
- }
- return error;
-}
-
-int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
-{
- /*
- * You can never reset a CPU clock, but we check for other errors
- * in the call before failing with EPERM.
- */
- int error = check_cpu_clock(which_clock);
- if (error == 0) {
- error = -EPERM;
- }
- return error;
-}
-
-
-/*
- * Sample a per-thread clock for the given task.
- */
-static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
- union cpu_time_count *cpu)
-{
- switch (POSIX_CLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case POSIX_CLOCK_PROF:
- cpu->cpu = prof_ticks(p);
- break;
- case POSIX_CLOCK_VIRT:
- cpu->cpu = virt_ticks(p);
- break;
- case POSIX_CLOCK_SCHED:
- cpu->sched = task_sched_runtime(p);
- break;
- }
- return 0;
-}
-
-void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
-{
- struct sighand_struct *sighand;
- struct signal_struct *sig;
- struct task_struct *t;
-
- *times = INIT_CPUTIME;
-
- rcu_read_lock();
- sighand = rcu_dereference(tsk->sighand);
- if (!sighand)
- goto out;
-
- sig = tsk->signal;
-
- t = tsk;
- do {
- times->utime = cputime_add(times->utime, t->utime);
- times->stime = cputime_add(times->stime, t->stime);
- times->sum_exec_runtime += t->se.sum_exec_runtime;
-
- t = next_thread(t);
- } while (t != tsk);
-
- times->utime = cputime_add(times->utime, sig->utime);
- times->stime = cputime_add(times->stime, sig->stime);
- times->sum_exec_runtime += sig->sum_sched_runtime;
-out:
- rcu_read_unlock();
-}
-
-static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
-{
- if (cputime_gt(b->utime, a->utime))
- a->utime = b->utime;
-
- if (cputime_gt(b->stime, a->stime))
- a->stime = b->stime;
-
- if (b->sum_exec_runtime > a->sum_exec_runtime)
- a->sum_exec_runtime = b->sum_exec_runtime;
-}
-
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
-{
- struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
- struct task_cputime sum;
- unsigned long flags;
-
- spin_lock_irqsave(&cputimer->lock, flags);
- if (!cputimer->running) {
- cputimer->running = 1;
- /*
- * The POSIX timer interface allows for absolute time expiry
- * values through the TIMER_ABSTIME flag, therefore we have
- * to synchronize the timer to the clock every time we start
- * it.
- */
- thread_group_cputime(tsk, &sum);
- update_gt_cputime(&cputimer->cputime, &sum);
- }
- *times = cputimer->cputime;
- spin_unlock_irqrestore(&cputimer->lock, flags);
-}
-
-/*
- * Sample a process (thread group) clock for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
- */
-static int cpu_clock_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- union cpu_time_count *cpu)
-{
- struct task_cputime cputime;
-
- switch (POSIX_CLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case POSIX_CLOCK_PROF:
- thread_group_cputime(p, &cputime);
- cpu->cpu = cputime_add(cputime.utime, cputime.stime);
- break;
- case POSIX_CLOCK_VIRT:
- thread_group_cputime(p, &cputime);
- cpu->cpu = cputime.utime;
- break;
- case POSIX_CLOCK_SCHED:
- cpu->sched = thread_group_sched_runtime(p);
- break;
- }
- return 0;
-}
-
-
-int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
-{
- const pid_t pid = POSIX_CLOCK_PID(which_clock);
- int error = -EINVAL;
- union cpu_time_count rtn;
-
- if (pid == 0) {
- /*
- * Special case constant value for our own clocks.
- * We don't have to do any lookup to find ourselves.
- */
- if (POSIX_CLOCK_PERTHREAD(which_clock)) {
- /*
- * Sampling just ourselves we can do with no locking.
- */
- error = cpu_clock_sample(which_clock,
- current, &rtn);
- } else {
- read_lock(&tasklist_lock);
- error = cpu_clock_sample_group(which_clock,
- current, &rtn);
- read_unlock(&tasklist_lock);
- }
- } else {
- /*
- * Find the given PID, and validate that the caller
- * should be able to see it.
- */
- struct task_struct *p;
- rcu_read_lock();
- p = find_task_by_vpid(pid);
- if (p) {
- if (POSIX_CLOCK_PERTHREAD(which_clock)) {
- if (thread_clock_allowed(p)) {
- error = cpu_clock_sample(which_clock,
- p, &rtn);
- }
- } else {
- read_lock(&tasklist_lock);
- if (process_clock_allowed(p) && p->sighand) {
- error =
- cpu_clock_sample_group(which_clock,
- p, &rtn);
- }
- read_unlock(&tasklist_lock);
- }
- }
- rcu_read_unlock();
- }
-
- if (error)
- return error;
- sample_to_timespec(which_clock, rtn, tp);
- return 0;
-}
-
-
-/*
- * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
- * This is called from sys_timer_create() and do_cpu_nanosleep() with the
- * new timer already all-zeros initialized.
- */
-int posix_cpu_timer_create(struct k_itimer *new_timer)
-{
- int ret = 0;
- const pid_t pid = POSIX_CLOCK_PID(new_timer->it_clock);
- struct task_struct *p;
-
- if (POSIX_CLOCK_WHICH(new_timer->it_clock) >= POSIX_CLOCK_MAX)
- return -EINVAL;
-
- INIT_LIST_HEAD(&new_timer->it.cpu.entry);
-
- read_lock(&tasklist_lock);
- if (POSIX_CLOCK_PERTHREAD(new_timer->it_clock)) {
- if (pid == 0) {
- p = current;
- } else {
- p = find_task_by_vpid(pid);
- if (p && !thread_clock_allowed(p))
- p = NULL;
- }
- } else {
- if (pid == 0) {
- p = current->group_leader;
- } else {
- p = find_task_by_vpid(pid);
- if (p && !process_clock_allowed(p))
- p = NULL;
- }
- }
- new_timer->it.cpu.task = p;
- if (p) {
- get_task_struct(p);
- } else {
- ret = -EINVAL;
- }
- read_unlock(&tasklist_lock);
-
- return ret;
-}
-
-/*
- * Clean up a CPU-clock timer that is about to be destroyed.
- * This is called from timer deletion with the timer already locked.
- * If we return TIMER_RETRY, it's necessary to release the timer's lock
- * and try again. (This happens when the timer is in the middle of firing.)
- */
-int posix_cpu_timer_del(struct k_itimer *timer)
-{
- struct task_struct *p = timer->it.cpu.task;
- int ret = 0;
-
- if (likely(p != NULL)) {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
- /*
- * We raced with the reaping of the task.
- * The deletion should have cleared us off the list.
- */
- BUG_ON(!list_empty(&timer->it.cpu.entry));
- } else {
- spin_lock(&p->sighand->siglock);
- if (timer->it.cpu.firing)
- ret = TIMER_RETRY;
- else
- list_del(&timer->it.cpu.entry);
- spin_unlock(&p->sighand->siglock);
- }
- read_unlock(&tasklist_lock);
-
- if (!ret)
- put_task_struct(p);
- }
-
- return ret;
-}
-
-/*
- * Clean out CPU timers still ticking when a thread exited. The task
- * pointer is cleared, and the expiry time is replaced with the residual
- * time for later timer_gettime calls to return.
- * This must be called with the siglock held.
- */
-static void cleanup_timers(struct list_head *head,
- cputime_t utime, cputime_t stime,
- unsigned long long sum_exec_runtime)
-{
- struct cpu_timer_list *timer, *next;
- cputime_t ptime = cputime_add(utime, stime);
-
- list_for_each_entry_safe(timer, next, head, entry) {
- list_del_init(&timer->entry);
- if (cputime_lt(timer->expires.cpu, ptime)) {
- timer->expires.cpu = cputime_zero;
- } else {
- timer->expires.cpu = cputime_sub(timer->expires.cpu,
- ptime);
- }
- }
-
- ++head;
- list_for_each_entry_safe(timer, next, head, entry) {
- list_del_init(&timer->entry);
- if (cputime_lt(timer->expires.cpu, utime)) {
- timer->expires.cpu = cputime_zero;
- } else {
- timer->expires.cpu = cputime_sub(timer->expires.cpu,
- utime);
- }
- }
-
- ++head;
- list_for_each_entry_safe(timer, next, head, entry) {
- list_del_init(&timer->entry);
- if (timer->expires.sched < sum_exec_runtime) {
- timer->expires.sched = 0;
- } else {
- timer->expires.sched -= sum_exec_runtime;
- }
- }
-}
-
-/*
- * These are both called with the siglock held, when the current thread
- * is being reaped. When the final (leader) thread in the group is reaped,
- * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
- */
-void posix_cpu_timers_exit(struct task_struct *tsk)
-{
- cleanup_timers(tsk->cpu_timers,
- tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
-
-}
-void posix_cpu_timers_exit_group(struct task_struct *tsk)
-{
- struct signal_struct *const sig = tsk->signal;
-
- cleanup_timers(tsk->signal->cpu_timers,
- cputime_add(tsk->utime, sig->utime),
- cputime_add(tsk->stime, sig->stime),
- tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
-}
-
-static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
-{
- /*
- * That's all for this thread or process.
- * We leave our residual in expires to be reported.
- */
- put_task_struct(timer->it.cpu.task);
- timer->it.cpu.task = NULL;
- timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
- timer->it.cpu.expires,
- now);
-}
-
-static inline int expires_gt(cputime_t expires, cputime_t new_exp)
-{
- return cputime_eq(expires, cputime_zero) ||
- cputime_gt(expires, new_exp);
-}
-
-/*
- * Insert the timer on the appropriate list before any timers that
- * expire later. This must be called with the tasklist_lock held
- * for reading, interrupts disabled and p->sighand->siglock taken.
- */
-static void arm_timer(struct k_itimer *timer)
-{
- struct task_struct *p = timer->it.cpu.task;
- struct list_head *head, *listpos;
- struct task_cputime *cputime_expires;
- struct cpu_timer_list *const nt = &timer->it.cpu;
- struct cpu_timer_list *next;
-
- if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
- head = p->cpu_timers;
- cputime_expires = &p->cputime_expires;
- } else {
- head = p->signal->cpu_timers;
- cputime_expires = &p->signal->cputime_expires;
- }
- head += POSIX_CLOCK_WHICH(timer->it_clock);
-
- listpos = head;
- list_for_each_entry(next, head, entry) {
- if (cpu_time_before(timer->it_clock, nt->expires, next->expires))
- break;
- listpos = &next->entry;
- }
- list_add(&nt->entry, listpos);
-
- if (listpos == head) {
- union cpu_time_count *exp = &nt->expires;
-
- /*
- * We are the new earliest-expiring POSIX 1.b timer, hence
- * need to update expiration cache. Take into account that
- * for process timers we share expiration cache with itimers
- * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
- */
-
- switch (POSIX_CLOCK_WHICH(timer->it_clock)) {
- case POSIX_CLOCK_PROF:
- if (expires_gt(cputime_expires->prof_exp, exp->cpu))
- cputime_expires->prof_exp = exp->cpu;
- break;
- case POSIX_CLOCK_VIRT:
- if (expires_gt(cputime_expires->virt_exp, exp->cpu))
- cputime_expires->virt_exp = exp->cpu;
- break;
- case POSIX_CLOCK_SCHED:
- if (cputime_expires->sched_exp == 0 ||
- cputime_expires->sched_exp > exp->sched)
- cputime_expires->sched_exp = exp->sched;
- break;
- }
- }
-}
-
-/*
- * The timer is locked, fire it and arrange for its reload.
- */
-static void cpu_timer_fire(struct k_itimer *timer)
-{
- if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
- /*
- * User don't want any signal.
- */
- timer->it.cpu.expires.sched = 0;
- } else if (unlikely(timer->sigq == NULL)) {
- /*
- * This a special case for clock_nanosleep,
- * not a normal timer from sys_timer_create.
- */
- wake_up_process(timer->it_process);
- timer->it.cpu.expires.sched = 0;
- } else if (timer->it.cpu.incr.sched == 0) {
- /*
- * One-shot timer. Clear it as soon as it's fired.
- */
- posix_timer_event(timer, 0);
- timer->it.cpu.expires.sched = 0;
- } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
- /*
- * The signal did not get queued because the signal
- * was ignored, so we won't get any callback to
- * reload the timer. But we need to keep it
- * ticking in case the signal is deliverable next time.
- */
- posix_cpu_timer_schedule(timer);
- }
-}
-
-/*
- * Sample a process (thread group) timer for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
- */
-static int cpu_timer_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- union cpu_time_count *cpu)
-{
- struct task_cputime cputime;
-
- thread_group_cputimer(p, &cputime);
- switch (POSIX_CLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case POSIX_CLOCK_PROF:
- cpu->cpu = cputime_add(cputime.utime, cputime.stime);
- break;
- case POSIX_CLOCK_VIRT:
- cpu->cpu = cputime.utime;
- break;
- case POSIX_CLOCK_SCHED:
- cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
- break;
- }
- return 0;
-}
-
-/*
- * Guts of sys_timer_settime for CPU timers.
- * This is called with the timer locked and interrupts disabled.
- * If we return TIMER_RETRY, it's necessary to release the timer's lock
- * and try again. (This happens when the timer is in the middle of firing.)
- */
-int posix_cpu_timer_set(struct k_itimer *timer, int flags,
- struct itimerspec *new, struct itimerspec *old)
-{
- struct task_struct *p = timer->it.cpu.task;
- union cpu_time_count old_expires, new_expires, old_incr, val;
- int ret;
-
- if (unlikely(p == NULL)) {
- /*
- * Timer refers to a dead task's clock.
- */
- return -ESRCH;
- }
-
- new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
-
- read_lock(&tasklist_lock);
- /*
- * We need the tasklist_lock to protect against reaping that
- * clears p->sighand. If p has just been reaped, we can no
- * longer get any information about it at all.
- */
- if (unlikely(p->sighand == NULL)) {
- read_unlock(&tasklist_lock);
- put_task_struct(p);
- timer->it.cpu.task = NULL;
- return -ESRCH;
- }
-
- /*
- * Disarm any old timer after extracting its expiry time.
- */
- BUG_ON(!irqs_disabled());
-
- ret = 0;
- old_incr = timer->it.cpu.incr;
- spin_lock(&p->sighand->siglock);
- old_expires = timer->it.cpu.expires;
- if (unlikely(timer->it.cpu.firing)) {
- timer->it.cpu.firing = -1;
- ret = TIMER_RETRY;
- } else
- list_del_init(&timer->it.cpu.entry);
-
- /*
- * We need to sample the current value to convert the new
- * value from to relative and absolute, and to convert the
- * old value from absolute to relative. To set a process
- * timer, we need a sample to balance the thread expiry
- * times (in arm_timer). With an absolute time, we must
- * check if it's already passed. In short, we need a sample.
- */
- if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &val);
- } else {
- cpu_timer_sample_group(timer->it_clock, p, &val);
- }
-
- if (old) {
- if (old_expires.sched == 0) {
- old->it_value.tv_sec = 0;
- old->it_value.tv_nsec = 0;
- } else {
- /*
- * Update the timer in case it has
- * overrun already. If it has,
- * we'll report it as having overrun
- * and with the next reloaded timer
- * already ticking, though we are
- * swallowing that pending
- * notification here to install the
- * new setting.
- */
- bump_cpu_timer(timer, val);
- if (cpu_time_before(timer->it_clock, val,
- timer->it.cpu.expires)) {
- old_expires = cpu_time_sub(
- timer->it_clock,
- timer->it.cpu.expires, val);
- sample_to_timespec(timer->it_clock,
- old_expires,
- &old->it_value);
- } else {
- old->it_value.tv_nsec = 1;
- old->it_value.tv_sec = 0;
- }
- }
- }
-
- if (unlikely(ret)) {
- /*
- * We are colliding with the timer actually firing.
- * Punt after filling in the timer's old value, and
- * disable this firing since we are already reporting
- * it as an overrun (thanks to bump_cpu_timer above).
- */
- spin_unlock(&p->sighand->siglock);
- read_unlock(&tasklist_lock);
- goto out;
- }
-
- if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
- cpu_time_add(timer->it_clock, &new_expires, val);
- }
-
- /*
- * Install the new expiry time (or zero).
- * For a timer with no notification action, we don't actually
- * arm the timer (we'll just fake it for timer_gettime).
- */
- timer->it.cpu.expires = new_expires;
- if (new_expires.sched != 0 &&
- cpu_time_before(timer->it_clock, val, new_expires)) {
- arm_timer(timer);
- }
-
- spin_unlock(&p->sighand->siglock);
- read_unlock(&tasklist_lock);
-
- /*
- * Install the new reload setting, and
- * set up the signal and overrun bookkeeping.
- */
- timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
- &new->it_interval);
-
- /*
- * This acts as a modification timestamp for the timer,
- * so any automatic reload attempt will punt on seeing
- * that we have reset the timer manually.
- */
- timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
- ~REQUEUE_PENDING;
- timer->it_overrun_last = 0;
- timer->it_overrun = -1;
-
- if (new_expires.sched != 0 &&
- !cpu_time_before(timer->it_clock, val, new_expires)) {
- /*
- * The designated time already passed, so we notify
- * immediately, even if the thread never runs to
- * accumulate more time on this clock.
- */
- cpu_timer_fire(timer);
- }
-
- ret = 0;
- out:
- if (old) {
- sample_to_timespec(timer->it_clock,
- old_incr, &old->it_interval);
- }
- return ret;
-}
-
-void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
-{
- union cpu_time_count now;
- struct task_struct *p = timer->it.cpu.task;
- int clear_dead;
-
- /*
- * Easy part: convert the reload time.
- */
- sample_to_timespec(timer->it_clock,
- timer->it.cpu.incr, &itp->it_interval);
-
- if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */
- itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
- return;
- }
-
- if (unlikely(p == NULL)) {
- /*
- * This task already died and the timer will never fire.
- * In this case, expires is actually the dead value.
- */
- dead:
- sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
- &itp->it_value);
- return;
- }
-
- /*
- * Sample the clock to take the difference with the expiry time.
- */
- if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
- clear_dead = p->exit_state;
- } else {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
- /*
- * The process has been reaped.
- * We can't even collect a sample any more.
- * Call the timer disarmed, nothing else to do.
- */
- put_task_struct(p);
- timer->it.cpu.task = NULL;
- timer->it.cpu.expires.sched = 0;
- read_unlock(&tasklist_lock);
- goto dead;
- } else {
- cpu_timer_sample_group(timer->it_clock, p, &now);
- clear_dead = (unlikely(p->exit_state) &&
- thread_group_empty(p));
- }
- read_unlock(&tasklist_lock);
- }
-
- if (unlikely(clear_dead)) {
- /*
- * We've noticed that the thread is dead, but
- * not yet reaped. Take this opportunity to
- * drop our task ref.
- */
- clear_dead_task(timer, now);
- goto dead;
- }
-
- if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
- sample_to_timespec(timer->it_clock,
- cpu_time_sub(timer->it_clock,
- timer->it.cpu.expires, now),
- &itp->it_value);
- } else {
- /*
- * The timer should have expired already, but the firing
- * hasn't taken place yet. Say it's just about to expire.
- */
- itp->it_value.tv_nsec = 1;
- itp->it_value.tv_sec = 0;
- }
-}
-
-/*
- * Check for any per-thread CPU timers that have fired and move them off
- * the tsk->cpu_timers[N] list onto the firing list. Here we update the
- * tsk->it_*_expires values to reflect the remaining thread CPU timers.
- */
-static void check_thread_timers(struct task_struct *tsk,
- struct list_head *firing)
-{
- int maxfire;
- struct list_head *timers = tsk->cpu_timers;
- struct signal_struct *const sig = tsk->signal;
- unsigned long soft;
-
- maxfire = 20;
- tsk->cputime_expires.prof_exp = cputime_zero;
- while (!list_empty(timers)) {
- struct cpu_timer_list *t = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
- tsk->cputime_expires.prof_exp = t->expires.cpu;
- break;
- }
- t->firing = 1;
- list_move_tail(&t->entry, firing);
- }
-
- ++timers;
- maxfire = 20;
- tsk->cputime_expires.virt_exp = cputime_zero;
- while (!list_empty(timers)) {
- struct cpu_timer_list *t = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
- tsk->cputime_expires.virt_exp = t->expires.cpu;
- break;
- }
- t->firing = 1;
- list_move_tail(&t->entry, firing);
- }
-
- ++timers;
- maxfire = 20;
- tsk->cputime_expires.sched_exp = 0;
- while (!list_empty(timers)) {
- struct cpu_timer_list *t = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
- tsk->cputime_expires.sched_exp = t->expires.sched;
- break;
- }
- t->firing = 1;
- list_move_tail(&t->entry, firing);
- }
-
- /*
- * Check for the special case thread timers.
- */
- soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
- if (soft != RLIM_INFINITY) {
- unsigned long hard =
- ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
-
- if (hard != RLIM_INFINITY &&
- tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
- /*
- * At the hard limit, we just die.
- * No need to calculate anything else now.
- */
- __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
- return;
- }
- if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
- /*
- * At the soft limit, send a SIGXCPU every second.
- */
- if (soft < hard) {
- soft += USEC_PER_SEC;
- sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
- }
- printk(KERN_INFO
- "RT Watchdog Timeout: %s[%d]\n",
- tsk->comm, task_pid_nr(tsk));
- __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
- }
- }
-}
-
-static void stop_process_timers(struct signal_struct *sig)
-{
- struct thread_group_cputimer *cputimer = &sig->cputimer;
- unsigned long flags;
-
- spin_lock_irqsave(&cputimer->lock, flags);
- cputimer->running = 0;
- spin_unlock_irqrestore(&cputimer->lock, flags);
-}
-
-static u32 onecputick;
-
-static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
- cputime_t *expires, cputime_t cur_time, int signo)
-{
- if (cputime_eq(it->expires, cputime_zero))
- return;
-
- if (cputime_ge(cur_time, it->expires)) {
- if (!cputime_eq(it->incr, cputime_zero)) {
- it->expires = cputime_add(it->expires, it->incr);
- it->error += it->incr_error;
- if (it->error >= onecputick) {
- it->expires = cputime_sub(it->expires,
- cputime_one_jiffy);
- it->error -= onecputick;
- }
- } else {
- it->expires = cputime_zero;
- }
-
- trace_itimer_expire(signo == SIGPROF ?
- ITIMER_PROF : ITIMER_VIRTUAL,
- tsk->signal->leader_pid, cur_time);
- __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
- }
-
- if (!cputime_eq(it->expires, cputime_zero) &&
- (cputime_eq(*expires, cputime_zero) ||
- cputime_lt(it->expires, *expires))) {
- *expires = it->expires;
- }
-}
-
-/**
- * task_cputime_zero - Check a task_cputime struct for all zero fields.
- *
- * @cputime: The struct to compare.
- *
- * Checks @cputime to see if all fields are zero. Returns true if all fields
- * are zero, false if any field is nonzero.
- */
-static inline int task_cputime_zero(const struct task_cputime *cputime)
-{
- if (cputime_eq(cputime->utime, cputime_zero) &&
- cputime_eq(cputime->stime, cputime_zero) &&
- cputime->sum_exec_runtime == 0)
- return 1;
- return 0;
-}
-
-/*
- * Check for any per-thread CPU timers that have fired and move them
- * off the tsk->*_timers list onto the firing list. Per-thread timers
- * have already been taken off.
- */
-static void check_process_timers(struct task_struct *tsk,
- struct list_head *firing)
-{
- int maxfire;
- struct signal_struct *const sig = tsk->signal;
- cputime_t utime, ptime, virt_expires, prof_expires;
- unsigned long long sum_sched_runtime, sched_expires;
- struct list_head *timers = sig->cpu_timers;
- struct task_cputime cputime;
- unsigned long soft;
-
- /*
- * Collect the current process totals.
- */
- thread_group_cputimer(tsk, &cputime);
- utime = cputime.utime;
- ptime = cputime_add(utime, cputime.stime);
- sum_sched_runtime = cputime.sum_exec_runtime;
- maxfire = 20;
- prof_expires = cputime_zero;
- while (!list_empty(timers)) {
- struct cpu_timer_list *tl = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
- prof_expires = tl->expires.cpu;
- break;
- }
- tl->firing = 1;
- list_move_tail(&tl->entry, firing);
- }
-
- ++timers;
- maxfire = 20;
- virt_expires = cputime_zero;
- while (!list_empty(timers)) {
- struct cpu_timer_list *tl = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
- virt_expires = tl->expires.cpu;
- break;
- }
- tl->firing = 1;
- list_move_tail(&tl->entry, firing);
- }
-
- ++timers;
- maxfire = 20;
- sched_expires = 0;
- while (!list_empty(timers)) {
- struct cpu_timer_list *tl = list_first_entry(timers,
- struct cpu_timer_list,
- entry);
- if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
- sched_expires = tl->expires.sched;
- break;
- }
- tl->firing = 1;
- list_move_tail(&tl->entry, firing);
- }
-
- /*
- * Check for the special case process timers.
- */
- check_cpu_itimer(tsk, &sig->it[POSIX_CLOCK_PROF], &prof_expires, ptime,
- SIGPROF);
- check_cpu_itimer(tsk, &sig->it[POSIX_CLOCK_VIRT], &virt_expires, utime,
- SIGVTALRM);
- soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
- if (soft != RLIM_INFINITY) {
- unsigned long psecs = cputime_to_secs(ptime);
- unsigned long hard =
- ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
- cputime_t x;
- if (psecs >= hard) {
- /*
- * At the hard limit, we just die.
- * No need to calculate anything else now.
- */
- __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
- return;
- }
- if (psecs >= soft) {
- /*
- * At the soft limit, send a SIGXCPU every second.
- */
- __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
- if (soft < hard) {
- soft++;
- sig->rlim[RLIMIT_CPU].rlim_cur = soft;
- }
- }
- x = secs_to_cputime(soft);
- if (cputime_eq(prof_expires, cputime_zero) ||
- cputime_lt(x, prof_expires)) {
- prof_expires = x;
- }
- }
-
- sig->cputime_expires.prof_exp = prof_expires;
- sig->cputime_expires.virt_exp = virt_expires;
- sig->cputime_expires.sched_exp = sched_expires;
- if (task_cputime_zero(&sig->cputime_expires))
- stop_process_timers(sig);
-}
-
-/*
- * This is called from the signal code (via do_schedule_next_timer)
- * when the last timer signal was delivered and we have to reload the timer.
- */
-void posix_cpu_timer_schedule(struct k_itimer *timer)
-{
- struct task_struct *p = timer->it.cpu.task;
- union cpu_time_count now;
-
- if (unlikely(p == NULL))
- /*
- * The task was cleaned up already, no future firings.
- */
- goto out;
-
- /*
- * Fetch the current sample and update the timer's expiry time.
- */
- if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
- bump_cpu_timer(timer, now);
- if (unlikely(p->exit_state)) {
- clear_dead_task(timer, now);
- goto out;
- }
- read_lock(&tasklist_lock); /* arm_timer needs it. */
- spin_lock(&p->sighand->siglock);
- } else {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
- /*
- * The process has been reaped.
- * We can't even collect a sample any more.
- */
- put_task_struct(p);
- timer->it.cpu.task = p = NULL;
- timer->it.cpu.expires.sched = 0;
- goto out_unlock;
- } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
- /*
- * We've noticed that the thread is dead, but
- * not yet reaped. Take this opportunity to
- * drop our task ref.
- */
- clear_dead_task(timer, now);
- goto out_unlock;
- }
- spin_lock(&p->sighand->siglock);
- cpu_timer_sample_group(timer->it_clock, p, &now);
- bump_cpu_timer(timer, now);
- /* Leave the tasklist_lock locked for the call below. */
- }
-
- /*
- * Now re-arm for the new expiry time.
- */
- BUG_ON(!irqs_disabled());
- arm_timer(timer);
- spin_unlock(&p->sighand->siglock);
-
-out_unlock:
- read_unlock(&tasklist_lock);
-
-out:
- timer->it_overrun_last = timer->it_overrun;
- timer->it_overrun = -1;
- ++timer->it_requeue_pending;
-}
-
-/**
- * task_cputime_expired - Compare two task_cputime entities.
- *
- * @sample: The task_cputime structure to be checked for expiration.
- * @expires: Expiration times, against which @sample will be checked.
- *
- * Checks @sample against @expires to see if any field of @sample has expired.
- * Returns true if any field of the former is greater than the corresponding
- * field of the latter if the latter field is set. Otherwise returns false.
- */
-static inline int task_cputime_expired(const struct task_cputime *sample,
- const struct task_cputime *expires)
-{
- if (!cputime_eq(expires->utime, cputime_zero) &&
- cputime_ge(sample->utime, expires->utime))
- return 1;
- if (!cputime_eq(expires->stime, cputime_zero) &&
- cputime_ge(cputime_add(sample->utime, sample->stime),
- expires->stime))
- return 1;
- if (expires->sum_exec_runtime != 0 &&
- sample->sum_exec_runtime >= expires->sum_exec_runtime)
- return 1;
- return 0;
-}
-
-/**
- * fastpath_timer_check - POSIX CPU timers fast path.
- *
- * @tsk: The task (thread) being checked.
- *
- * Check the task and thread group timers. If both are zero (there are no
- * timers set) return false. Otherwise snapshot the task and thread group
- * timers and compare them with the corresponding expiration times. Return
- * true if a timer has expired, else return false.
- */
-static inline int fastpath_timer_check(struct task_struct *tsk)
-{
- struct signal_struct *sig;
-
- /* tsk == current, ensure it is safe to use ->signal/sighand */
- if (unlikely(tsk->exit_state))
- return 0;
-
- if (!task_cputime_zero(&tsk->cputime_expires)) {
- struct task_cputime task_sample = {
- .utime = tsk->utime,
- .stime = tsk->stime,
- .sum_exec_runtime = tsk->se.sum_exec_runtime
- };
-
- if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
- return 1;
- }
-
- sig = tsk->signal;
- if (sig->cputimer.running) {
- struct task_cputime group_sample;
-
- thread_group_cputimer(tsk, &group_sample);
- if (task_cputime_expired(&group_sample, &sig->cputime_expires))
- return 1;
- }
-
- return 0;
-}
-
-/*
- * This is called from the timer interrupt handler. The irq handler has
- * already updated our counts. We need to check if any timers fire now.
- * Interrupts are disabled.
- */
-void run_posix_cpu_timers(struct task_struct *tsk)
-{
- LIST_HEAD(firing);
- struct k_itimer *timer, *next;
-
- BUG_ON(!irqs_disabled());
-
- /*
- * The fast path checks that there are no expired thread or thread
- * group timers. If that's so, just return.
- */
- if (!fastpath_timer_check(tsk))
- return;
-
- spin_lock(&tsk->sighand->siglock);
- /*
- * Here we take off tsk->signal->cpu_timers[N] and
- * tsk->cpu_timers[N] all the timers that are firing, and
- * put them on the firing list.
- */
- check_thread_timers(tsk, &firing);
- /*
- * If there are any active process wide timers (POSIX 1.b, itimers,
- * RLIMIT_CPU) cputimer must be running.
- */
- if (tsk->signal->cputimer.running)
- check_process_timers(tsk, &firing);
-
- /*
- * We must release these locks before taking any timer's lock.
- * There is a potential race with timer deletion here, as the
- * siglock now protects our private firing list. We have set
- * the firing flag in each timer, so that a deletion attempt
- * that gets the timer lock before we do will give it up and
- * spin until we've taken care of that timer below.
- */
- spin_unlock(&tsk->sighand->siglock);
-
- /*
- * Now that all the timers on our list have the firing flag,
- * noone will touch their list entries but us. We'll take
- * each timer's lock before clearing its firing flag, so no
- * timer call will interfere.
- */
- list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
- int cpu_firing;
-
- spin_lock(&timer->it_lock);
- list_del_init(&timer->it.cpu.entry);
- cpu_firing = timer->it.cpu.firing;
- timer->it.cpu.firing = 0;
- /*
- * The firing flag is -1 if we collided with a reset
- * of the timer, which already reported this
- * almost-firing as an overrun. So don't generate an event.
- */
- if (likely(cpu_firing >= 0))
- cpu_timer_fire(timer);
- spin_unlock(&timer->it_lock);
- }
-}
-
-/*
- * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
- * The tsk->sighand->siglock must be held by the caller.
- */
-void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
- cputime_t *newval, cputime_t *oldval)
-{
- union cpu_time_count now;
-
- BUG_ON(clock_idx == POSIX_CLOCK_SCHED);
- cpu_timer_sample_group(clock_idx, tsk, &now);
-
- if (oldval) {
- /*
- * We are setting itimer. The *oldval is absolute and we update
- * it to be relative, *newval argument is relative and we update
- * it to be absolute.
- */
- if (!cputime_eq(*oldval, cputime_zero)) {
- if (cputime_le(*oldval, now.cpu)) {
- /* Just about to fire. */
- *oldval = cputime_one_jiffy;
- } else {
- *oldval = cputime_sub(*oldval, now.cpu);
- }
- }
-
- if (cputime_eq(*newval, cputime_zero))
- return;
- *newval = cputime_add(*newval, now.cpu);
- }
-
- /*
- * Update expiration cache if we are the earliest timer, or eventually
- * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
- */
- switch (clock_idx) {
- case POSIX_CLOCK_PROF:
- if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
- tsk->signal->cputime_expires.prof_exp = *newval;
- break;
- case POSIX_CLOCK_VIRT:
- if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
- tsk->signal->cputime_expires.virt_exp = *newval;
- break;
- }
-}
-
-static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp, struct itimerspec *it)
-{
- struct k_itimer timer;
- int error;
-
- /*
- * Set up a temporary timer and then wait for it to go off.
- */
- memset(&timer, 0, sizeof timer);
- spin_lock_init(&timer.it_lock);
- timer.it_clock = which_clock;
- timer.it_overrun = -1;
- error = posix_cpu_timer_create(&timer);
- timer.it_process = current;
- if (!error) {
- static struct itimerspec zero_it;
-
- memset(it, 0, sizeof *it);
- it->it_value = *rqtp;
-
- spin_lock_irq(&timer.it_lock);
- error = posix_cpu_timer_set(&timer, flags, it, NULL);
- if (error) {
- spin_unlock_irq(&timer.it_lock);
- return error;
- }
-
- while (!signal_pending(current)) {
- if (timer.it.cpu.expires.sched == 0) {
- /*
- * Our timer fired and was reset.
- */
- spin_unlock_irq(&timer.it_lock);
- return 0;
- }
-
- /*
- * Block until cpu_timer_fire (or a signal) wakes us.
- */
- __set_current_state(TASK_INTERRUPTIBLE);
- spin_unlock_irq(&timer.it_lock);
- schedule();
- spin_lock_irq(&timer.it_lock);
- }
-
- /*
- * We were interrupted by a signal.
- */
- sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
- posix_cpu_timer_set(&timer, 0, &zero_it, it);
- spin_unlock_irq(&timer.it_lock);
-
- if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
- /*
- * It actually did fire already.
- */
- return 0;
- }
-
- error = -ERESTART_RESTARTBLOCK;
- }
-
- return error;
-}
-
-int posix_cpu_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp, struct timespec __user *rmtp)
-{
- struct restart_block *restart_block =
- ¤t_thread_info()->restart_block;
- struct itimerspec it;
- int error;
-
- /*
- * Diagnose required errors first.
- */
- if (POSIX_CLOCK_PERTHREAD(which_clock) &&
- (POSIX_CLOCK_PID(which_clock) == 0 ||
- POSIX_CLOCK_PID(which_clock) == current->pid))
- return -EINVAL;
-
- error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
-
- if (error == -ERESTART_RESTARTBLOCK) {
-
- if (flags & TIMER_ABSTIME)
- return -ERESTARTNOHAND;
- /*
- * Report back to the user the time still remaining.
- */
- if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
- return -EFAULT;
-
- restart_block->fn = posix_cpu_nsleep_restart;
- restart_block->arg0 = which_clock;
- restart_block->arg1 = (unsigned long) rmtp;
- restart_block->arg2 = rqtp->tv_sec;
- restart_block->arg3 = rqtp->tv_nsec;
- }
- return error;
-}
-
-long posix_cpu_nsleep_restart(struct restart_block *restart_block)
-{
- clockid_t which_clock = restart_block->arg0;
- struct timespec __user *rmtp;
- struct timespec t;
- struct itimerspec it;
- int error;
-
- rmtp = (struct timespec __user *) restart_block->arg1;
- t.tv_sec = restart_block->arg2;
- t.tv_nsec = restart_block->arg3;
-
- restart_block->fn = do_no_restart_syscall;
- error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
-
- if (error == -ERESTART_RESTARTBLOCK) {
- /*
- * Report back to the user the time still remaining.
- */
- if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
- return -EFAULT;
-
- restart_block->fn = posix_cpu_nsleep_restart;
- restart_block->arg0 = which_clock;
- restart_block->arg1 = (unsigned long) rmtp;
- restart_block->arg2 = t.tv_sec;
- restart_block->arg3 = t.tv_nsec;
- }
- return error;
-
-}
-
-
-#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, POSIX_CLOCK_SCHED)
-#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, POSIX_CLOCK_SCHED)
-
-static int process_cpu_clock_getres(const clockid_t which_clock,
- struct timespec *tp)
-{
- return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
-}
-static int process_cpu_clock_get(const clockid_t which_clock,
- struct timespec *tp)
-{
- return posix_cpu_clock_get(PROCESS_CLOCK, tp);
-}
-static int process_cpu_timer_create(struct k_itimer *timer)
-{
- timer->it_clock = PROCESS_CLOCK;
- return posix_cpu_timer_create(timer);
-}
-static int process_cpu_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp,
- struct timespec __user *rmtp)
-{
- return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
-}
-static long process_cpu_nsleep_restart(struct restart_block *restart_block)
-{
- return -EINVAL;
-}
-static int thread_cpu_clock_getres(const clockid_t which_clock,
- struct timespec *tp)
-{
- return posix_cpu_clock_getres(THREAD_CLOCK, tp);
-}
-static int thread_cpu_clock_get(const clockid_t which_clock,
- struct timespec *tp)
-{
- return posix_cpu_clock_get(THREAD_CLOCK, tp);
-}
-static int thread_cpu_timer_create(struct k_itimer *timer)
-{
- timer->it_clock = THREAD_CLOCK;
- return posix_cpu_timer_create(timer);
-}
-static int thread_cpu_nsleep(const clockid_t which_clock, int flags,
- struct timespec *rqtp, struct timespec __user *rmtp)
-{
- return -EINVAL;
-}
-static long thread_cpu_nsleep_restart(struct restart_block *restart_block)
-{
- return -EINVAL;
-}
-
-static __init int init_posix_cpu_timers(void)
-{
- struct k_clock cpu_process = {
- .clock_getres = process_cpu_clock_getres,
- .clock_get = process_cpu_clock_get,
- .clock_set = do_posix_clock_nosettime,
- .timer_create = process_cpu_timer_create,
- .nsleep = process_cpu_nsleep,
- .nsleep_restart = process_cpu_nsleep_restart,
- };
- struct k_clock cpu_thread = {
- .clock_getres = thread_cpu_clock_getres,
- .clock_get = thread_cpu_clock_get,
- .clock_set = do_posix_clock_nosettime,
- .timer_create = thread_cpu_timer_create,
- .nsleep = thread_cpu_nsleep,
- .nsleep_restart = thread_cpu_nsleep_restart,
- };
- struct k_clock wall_process = {
- .clock_getres = process_wall_getres,
- .clock_get = process_wall_get,
- .clock_set = wall_clock_set,
- .timer_create = wall_timer_create,
- .nsleep = process_wall_nsleep,
- .nsleep_restart = process_wall_nsleep_restart,
- };
- struct k_clock wall_thread = {
- .clock_getres = thread_wall_getres,
- .clock_get = thread_wall_get,
- .clock_set = wall_clock_set,
- .timer_create = wall_timer_create,
- .nsleep = thread_wall_nsleep,
- .nsleep_restart = thread_wall_nsleep_restart,
- };
- struct timespec ts;
-
- register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &cpu_process);
- register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &cpu_thread);
- register_posix_clock(CLOCK_PROCESS_WALLTIME_ID, &wall_process);
- register_posix_clock(CLOCK_THREAD_WALLTIME_ID, &wall_thread);
-
- cputime_to_timespec(cputime_one_jiffy, &ts);
- onecputick = ts.tv_nsec;
- WARN_ON(ts.tv_sec != 0);
-
- return 0;
-}
-__initcall(init_posix_cpu_timers);
diff --git a/kernel/posix-task-timers.c b/kernel/posix-task-timers.c
new file mode 100644
index 0000000..88c2f4c
--- /dev/null
+++ b/kernel/posix-task-timers.c
@@ -0,0 +1,1852 @@
+/*
+ * Implementation of CPU time and wall time clocks.
+ */
+
+#include <linux/sched.h>
+#include <linux/posix-timers.h>
+#include <linux/errno.h>
+#include <linux/math64.h>
+#include <asm/uaccess.h>
+#include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
+
+/*
+ * Called after updating RLIMIT_CPU to run cpu timer and update
+ * tsk->signal->cputime_expires expiration cache if necessary. Needs
+ * siglock protection since other code may update expiration cache as
+ * well.
+ */
+void update_rlimit_cpu(unsigned long rlim_new)
+{
+ cputime_t cputime = secs_to_cputime(rlim_new);
+
+ spin_lock_irq(¤t->sighand->siglock);
+ set_process_cpu_timer(current, POSIX_CLOCK_PROF, &cputime, NULL);
+ spin_unlock_irq(¤t->sighand->siglock);
+}
+
+/* RCU lock needed */
+static int thread_clock_allowed(struct task_struct *p)
+{
+ const struct cred *cred, *pcred;
+
+ if (unlikely(capable(CAP_SYS_ADMIN)))
+ return 1;
+ cred = current_cred();
+ pcred = __task_cred(p);
+
+ return (cred->euid == pcred->euid ||
+ cred->euid == pcred->uid);
+}
+
+/* RCU read lock needed */
+static inline int process_clock_allowed(struct task_struct *p)
+{
+ return thread_group_leader(p);
+}
+
+static int check_task_clock(const clockid_t which_clock)
+{
+ int error = 0;
+ struct task_struct *p;
+ const pid_t pid = POSIX_CLOCK_PID(which_clock);
+
+ if (pid == 0)
+ return 0;
+
+ rcu_read_lock();
+ p = find_task_by_vpid(pid);
+ if (!p || !(POSIX_CLOCK_PERTHREAD(which_clock) ?
+ thread_clock_allowed(p) : process_clock_allowed(p))) {
+ error = -EINVAL;
+ }
+ rcu_read_unlock();
+
+ return error;
+}
+
+static inline int check_cpu_clock(const clockid_t which_clock)
+{
+ return !IS_CPU_CLOCK(which_clock) ?
+ -EINVAL : check_task_clock(which_clock);
+}
+
+static inline int check_wall_clock(const clockid_t which_clock)
+{
+ return !IS_WALL_CLOCK(which_clock) ?
+ -EINVAL : check_task_clock(which_clock);
+}
+
+/* Wall time clocks */
+
+/* Get the start time of the process/thread referenced by the wall clock.
+ * RCU lock required. */
+
+static int get_start_time(clockid_t which_clock, struct timespec *start)
+{
+ struct task_struct *p =
+ find_task_by_vpid(POSIX_CLOCK_PID(which_clock));
+ if (p && (
+ (POSIX_CLOCK_PERTHREAD(which_clock) &&
+ thread_clock_allowed(p)) ||
+ (!POSIX_CLOCK_PERTHREAD(which_clock) &&
+ process_clock_allowed(p) && p->sighand))) {
+ *start = p->start_time;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+/* monotonic clock is used to get start_time and uptime
+ * so the precision is twice the precision of the monotonic clock */
+
+int wall_clock_getres(clockid_t which_clock, struct timespec *tp)
+{
+ int error = check_wall_clock(which_clock);
+ if (error)
+ return error;
+ error = hrtimer_get_res(CLOCK_MONOTONIC, tp);
+ if (error)
+ return error;
+ *tp = timespec_add_safe(*tp, *tp);
+ return 0;
+}
+
+int wall_clock_get(clockid_t which_clock, struct timespec *tp)
+{
+ struct timespec uptime, start;
+ int error = -EINVAL;
+
+ if (!IS_WALL_CLOCK(which_clock))
+ return error;
+
+ if (POSIX_CLOCK_PID(which_clock) == 0) {
+ start = (POSIX_CLOCK_PERTHREAD(which_clock) ?
+ current : current->group_leader)->start_time;
+ error = 0;
+ } else {
+ rcu_read_lock();
+ error = get_start_time(which_clock, &start);
+ rcu_read_unlock();
+ }
+
+ if (error)
+ return error;
+
+ do_posix_clock_monotonic_gettime(&uptime);
+ *tp = timespec_sub(uptime, start);
+
+ return 0;
+}
+
+int wall_clock_set(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return check_wall_clock(which_clock) ?: -EPERM;
+}
+
+int wall_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *tsave, struct timespec __user *rmtp)
+{
+ if (!IS_WALL_CLOCK(which_clock))
+ return -EINVAL;
+
+ if (flags & TIMER_ABSTIME) {
+ int error;
+ struct timespec start;
+
+ rcu_read_lock();
+ error = get_start_time(which_clock, &start);
+ rcu_read_unlock();
+
+ if (error)
+ return error;
+ *tsave = timespec_add_safe(*tsave, start);
+ }
+ return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+ CLOCK_MONOTONIC);
+}
+
+long wall_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+
+int wall_timer_get(struct k_itimer *timr,
+ struct itimerspec *cur_setting)
+{
+ return -EINVAL;
+}
+
+int wall_timer_create(struct k_itimer *new_timer)
+{
+ return -EINVAL;
+}
+
+int wall_timer_set(struct k_itimer *timr, int flags,
+ struct itimerspec *new_setting,
+ struct itimerspec *old_setting)
+{
+ return -EINVAL;
+}
+
+int wall_timer_del(struct k_itimer *timer)
+{
+ return -EINVAL;
+}
+
+#define PROCESS_WALLCLOCK MAKE_PROCESS_WALLCLOCK(0)
+#define THREAD_WALLCLOCK MAKE_THREAD_WALLCLOCK(0)
+
+static int process_wall_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return wall_clock_getres(PROCESS_WALLCLOCK, tp);
+}
+static int process_wall_get(const clockid_t which_clock, struct timespec *tp)
+{
+ return wall_clock_get(PROCESS_WALLCLOCK, tp);
+}
+static int process_wall_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp,
+ struct timespec __user *rmtp)
+{
+ return wall_nsleep(PROCESS_WALLCLOCK, flags, rqtp, rmtp);
+}
+static long process_wall_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+static int thread_wall_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return wall_clock_getres(THREAD_WALLCLOCK, tp);
+}
+static int thread_wall_get(const clockid_t which_clock, struct timespec *tp)
+{
+ return wall_clock_get(THREAD_WALLCLOCK, tp);
+}
+static int thread_wall_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp,
+ struct timespec __user *rmtp)
+{
+ return wall_nsleep(THREAD_WALLCLOCK, flags, rqtp, rmtp);
+}
+static long thread_wall_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+
+/* CPU time clocks */
+
+static inline union cpu_time_count
+timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
+{
+ union cpu_time_count ret;
+ ret.sched = 0; /* high half always zero when .cpu used */
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
+ ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
+ } else {
+ ret.cpu = timespec_to_cputime(tp);
+ }
+ return ret;
+}
+
+static void sample_to_timespec(const clockid_t which_clock,
+ union cpu_time_count cpu,
+ struct timespec *tp)
+{
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED)
+ *tp = ns_to_timespec(cpu.sched);
+ else
+ cputime_to_timespec(cpu.cpu, tp);
+}
+
+static inline int cpu_time_before(const clockid_t which_clock,
+ union cpu_time_count now,
+ union cpu_time_count then)
+{
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
+ return now.sched < then.sched;
+ } else {
+ return cputime_lt(now.cpu, then.cpu);
+ }
+}
+static inline void cpu_time_add(const clockid_t which_clock,
+ union cpu_time_count *acc,
+ union cpu_time_count val)
+{
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
+ acc->sched += val.sched;
+ } else {
+ acc->cpu = cputime_add(acc->cpu, val.cpu);
+ }
+}
+static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
+ union cpu_time_count a,
+ union cpu_time_count b)
+{
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
+ a.sched -= b.sched;
+ } else {
+ a.cpu = cputime_sub(a.cpu, b.cpu);
+ }
+ return a;
+}
+
+/*
+ * Divide and limit the result to res >= 1
+ *
+ * This is necessary to prevent signal delivery starvation, when the result of
+ * the division would be rounded down to 0.
+ */
+static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
+{
+ cputime_t res = cputime_div(time, div);
+
+ return max_t(cputime_t, res, 1);
+}
+
+/*
+ * Update expiry time from increment, and increase overrun count,
+ * given the current clock sample.
+ */
+static void bump_cpu_timer(struct k_itimer *timer,
+ union cpu_time_count now)
+{
+ int i;
+
+ if (timer->it.cpu.incr.sched == 0)
+ return;
+
+ if (POSIX_CLOCK_WHICH(timer->it_clock) == POSIX_CLOCK_SCHED) {
+ unsigned long long delta, incr;
+
+ if (now.sched < timer->it.cpu.expires.sched)
+ return;
+ incr = timer->it.cpu.incr.sched;
+ delta = now.sched + incr - timer->it.cpu.expires.sched;
+ /* Don't use (incr*2 < delta), incr*2 might overflow. */
+ for (i = 0; incr < delta - incr; i++)
+ incr = incr << 1;
+ for (; i >= 0; incr >>= 1, i--) {
+ if (delta < incr)
+ continue;
+ timer->it.cpu.expires.sched += incr;
+ timer->it_overrun += 1 << i;
+ delta -= incr;
+ }
+ } else {
+ cputime_t delta, incr;
+
+ if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
+ return;
+ incr = timer->it.cpu.incr.cpu;
+ delta = cputime_sub(cputime_add(now.cpu, incr),
+ timer->it.cpu.expires.cpu);
+ /* Don't use (incr*2 < delta), incr*2 might overflow. */
+ for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
+ incr = cputime_add(incr, incr);
+ for (; i >= 0; incr = cputime_halve(incr), i--) {
+ if (cputime_lt(delta, incr))
+ continue;
+ timer->it.cpu.expires.cpu =
+ cputime_add(timer->it.cpu.expires.cpu, incr);
+ timer->it_overrun += 1 << i;
+ delta = cputime_sub(delta, incr);
+ }
+ }
+}
+
+static inline cputime_t prof_ticks(struct task_struct *p)
+{
+ return cputime_add(p->utime, p->stime);
+}
+static inline cputime_t virt_ticks(struct task_struct *p)
+{
+ return p->utime;
+}
+
+int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
+{
+ int error = check_cpu_clock(which_clock);
+ if (!error) {
+ tp->tv_sec = 0;
+ tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
+ if (POSIX_CLOCK_WHICH(which_clock) == POSIX_CLOCK_SCHED) {
+ /*
+ * If sched_clock is using a cycle counter, we
+ * don't have any idea of its true resolution
+ * exported, but it is much more than 1s/HZ.
+ */
+ tp->tv_nsec = 1;
+ }
+ }
+ return error;
+}
+
+int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
+{
+ /*
+ * You can never reset a CPU clock, but we check for other errors
+ * in the call before failing with EPERM.
+ */
+ int error = check_cpu_clock(which_clock);
+ if (error == 0) {
+ error = -EPERM;
+ }
+ return error;
+}
+
+
+/*
+ * Sample a per-thread clock for the given task.
+ */
+static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ switch (POSIX_CLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case POSIX_CLOCK_PROF:
+ cpu->cpu = prof_ticks(p);
+ break;
+ case POSIX_CLOCK_VIRT:
+ cpu->cpu = virt_ticks(p);
+ break;
+ case POSIX_CLOCK_SCHED:
+ cpu->sched = task_sched_runtime(p);
+ break;
+ }
+ return 0;
+}
+
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
+{
+ struct sighand_struct *sighand;
+ struct signal_struct *sig;
+ struct task_struct *t;
+
+ *times = INIT_CPUTIME;
+
+ rcu_read_lock();
+ sighand = rcu_dereference(tsk->sighand);
+ if (!sighand)
+ goto out;
+
+ sig = tsk->signal;
+
+ t = tsk;
+ do {
+ times->utime = cputime_add(times->utime, t->utime);
+ times->stime = cputime_add(times->stime, t->stime);
+ times->sum_exec_runtime += t->se.sum_exec_runtime;
+
+ t = next_thread(t);
+ } while (t != tsk);
+
+ times->utime = cputime_add(times->utime, sig->utime);
+ times->stime = cputime_add(times->stime, sig->stime);
+ times->sum_exec_runtime += sig->sum_sched_runtime;
+out:
+ rcu_read_unlock();
+}
+
+static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
+{
+ if (cputime_gt(b->utime, a->utime))
+ a->utime = b->utime;
+
+ if (cputime_gt(b->stime, a->stime))
+ a->stime = b->stime;
+
+ if (b->sum_exec_runtime > a->sum_exec_runtime)
+ a->sum_exec_runtime = b->sum_exec_runtime;
+}
+
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+{
+ struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+ struct task_cputime sum;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cputimer->lock, flags);
+ if (!cputimer->running) {
+ cputimer->running = 1;
+ /*
+ * The POSIX timer interface allows for absolute time expiry
+ * values through the TIMER_ABSTIME flag, therefore we have
+ * to synchronize the timer to the clock every time we start
+ * it.
+ */
+ thread_group_cputime(tsk, &sum);
+ update_gt_cputime(&cputimer->cputime, &sum);
+ }
+ *times = cputimer->cputime;
+ spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
+/*
+ * Sample a process (thread group) clock for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ */
+static int cpu_clock_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ struct task_cputime cputime;
+
+ switch (POSIX_CLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case POSIX_CLOCK_PROF:
+ thread_group_cputime(p, &cputime);
+ cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+ break;
+ case POSIX_CLOCK_VIRT:
+ thread_group_cputime(p, &cputime);
+ cpu->cpu = cputime.utime;
+ break;
+ case POSIX_CLOCK_SCHED:
+ cpu->sched = thread_group_sched_runtime(p);
+ break;
+ }
+ return 0;
+}
+
+
+int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
+{
+ const pid_t pid = POSIX_CLOCK_PID(which_clock);
+ int error = -EINVAL;
+ union cpu_time_count rtn;
+
+ if (pid == 0) {
+ /*
+ * Special case constant value for our own clocks.
+ * We don't have to do any lookup to find ourselves.
+ */
+ if (POSIX_CLOCK_PERTHREAD(which_clock)) {
+ /*
+ * Sampling just ourselves we can do with no locking.
+ */
+ error = cpu_clock_sample(which_clock,
+ current, &rtn);
+ } else {
+ read_lock(&tasklist_lock);
+ error = cpu_clock_sample_group(which_clock,
+ current, &rtn);
+ read_unlock(&tasklist_lock);
+ }
+ } else {
+ /*
+ * Find the given PID, and validate that the caller
+ * should be able to see it.
+ */
+ struct task_struct *p;
+ rcu_read_lock();
+ p = find_task_by_vpid(pid);
+ if (p) {
+ if (POSIX_CLOCK_PERTHREAD(which_clock)) {
+ if (thread_clock_allowed(p)) {
+ error = cpu_clock_sample(which_clock,
+ p, &rtn);
+ }
+ } else {
+ read_lock(&tasklist_lock);
+ if (process_clock_allowed(p) && p->sighand) {
+ error =
+ cpu_clock_sample_group(which_clock,
+ p, &rtn);
+ }
+ read_unlock(&tasklist_lock);
+ }
+ }
+ rcu_read_unlock();
+ }
+
+ if (error)
+ return error;
+ sample_to_timespec(which_clock, rtn, tp);
+ return 0;
+}
+
+
+/*
+ * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
+ * This is called from sys_timer_create() and do_cpu_nanosleep() with the
+ * new timer already all-zeros initialized.
+ */
+int posix_cpu_timer_create(struct k_itimer *new_timer)
+{
+ int ret = 0;
+ const pid_t pid = POSIX_CLOCK_PID(new_timer->it_clock);
+ struct task_struct *p;
+
+ if (POSIX_CLOCK_WHICH(new_timer->it_clock) >= POSIX_CLOCK_MAX)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&new_timer->it.cpu.entry);
+
+ read_lock(&tasklist_lock);
+ if (POSIX_CLOCK_PERTHREAD(new_timer->it_clock)) {
+ if (pid == 0) {
+ p = current;
+ } else {
+ p = find_task_by_vpid(pid);
+ if (p && !thread_clock_allowed(p))
+ p = NULL;
+ }
+ } else {
+ if (pid == 0) {
+ p = current->group_leader;
+ } else {
+ p = find_task_by_vpid(pid);
+ if (p && !process_clock_allowed(p))
+ p = NULL;
+ }
+ }
+ new_timer->it.cpu.task = p;
+ if (p) {
+ get_task_struct(p);
+ } else {
+ ret = -EINVAL;
+ }
+ read_unlock(&tasklist_lock);
+
+ return ret;
+}
+
+/*
+ * Clean up a CPU-clock timer that is about to be destroyed.
+ * This is called from timer deletion with the timer already locked.
+ * If we return TIMER_RETRY, it's necessary to release the timer's lock
+ * and try again. (This happens when the timer is in the middle of firing.)
+ */
+int posix_cpu_timer_del(struct k_itimer *timer)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ int ret = 0;
+
+ if (likely(p != NULL)) {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->sighand == NULL)) {
+ /*
+ * We raced with the reaping of the task.
+ * The deletion should have cleared us off the list.
+ */
+ BUG_ON(!list_empty(&timer->it.cpu.entry));
+ } else {
+ spin_lock(&p->sighand->siglock);
+ if (timer->it.cpu.firing)
+ ret = TIMER_RETRY;
+ else
+ list_del(&timer->it.cpu.entry);
+ spin_unlock(&p->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+
+ if (!ret)
+ put_task_struct(p);
+ }
+
+ return ret;
+}
+
+/*
+ * Clean out CPU timers still ticking when a thread exited. The task
+ * pointer is cleared, and the expiry time is replaced with the residual
+ * time for later timer_gettime calls to return.
+ * This must be called with the siglock held.
+ */
+static void cleanup_timers(struct list_head *head,
+ cputime_t utime, cputime_t stime,
+ unsigned long long sum_exec_runtime)
+{
+ struct cpu_timer_list *timer, *next;
+ cputime_t ptime = cputime_add(utime, stime);
+
+ list_for_each_entry_safe(timer, next, head, entry) {
+ list_del_init(&timer->entry);
+ if (cputime_lt(timer->expires.cpu, ptime)) {
+ timer->expires.cpu = cputime_zero;
+ } else {
+ timer->expires.cpu = cputime_sub(timer->expires.cpu,
+ ptime);
+ }
+ }
+
+ ++head;
+ list_for_each_entry_safe(timer, next, head, entry) {
+ list_del_init(&timer->entry);
+ if (cputime_lt(timer->expires.cpu, utime)) {
+ timer->expires.cpu = cputime_zero;
+ } else {
+ timer->expires.cpu = cputime_sub(timer->expires.cpu,
+ utime);
+ }
+ }
+
+ ++head;
+ list_for_each_entry_safe(timer, next, head, entry) {
+ list_del_init(&timer->entry);
+ if (timer->expires.sched < sum_exec_runtime) {
+ timer->expires.sched = 0;
+ } else {
+ timer->expires.sched -= sum_exec_runtime;
+ }
+ }
+}
+
+/*
+ * These are both called with the siglock held, when the current thread
+ * is being reaped. When the final (leader) thread in the group is reaped,
+ * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
+ */
+void posix_cpu_timers_exit(struct task_struct *tsk)
+{
+ cleanup_timers(tsk->cpu_timers,
+ tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
+
+}
+void posix_cpu_timers_exit_group(struct task_struct *tsk)
+{
+ struct signal_struct *const sig = tsk->signal;
+
+ cleanup_timers(tsk->signal->cpu_timers,
+ cputime_add(tsk->utime, sig->utime),
+ cputime_add(tsk->stime, sig->stime),
+ tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
+}
+
+static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
+{
+ /*
+ * That's all for this thread or process.
+ * We leave our residual in expires to be reported.
+ */
+ put_task_struct(timer->it.cpu.task);
+ timer->it.cpu.task = NULL;
+ timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
+ timer->it.cpu.expires,
+ now);
+}
+
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+ return cputime_eq(expires, cputime_zero) ||
+ cputime_gt(expires, new_exp);
+}
+
+/*
+ * Insert the timer on the appropriate list before any timers that
+ * expire later. This must be called with the tasklist_lock held
+ * for reading, interrupts disabled and p->sighand->siglock taken.
+ */
+static void arm_timer(struct k_itimer *timer)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ struct list_head *head, *listpos;
+ struct task_cputime *cputime_expires;
+ struct cpu_timer_list *const nt = &timer->it.cpu;
+ struct cpu_timer_list *next;
+
+ if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
+ head = p->cpu_timers;
+ cputime_expires = &p->cputime_expires;
+ } else {
+ head = p->signal->cpu_timers;
+ cputime_expires = &p->signal->cputime_expires;
+ }
+ head += POSIX_CLOCK_WHICH(timer->it_clock);
+
+ listpos = head;
+ list_for_each_entry(next, head, entry) {
+ if (cpu_time_before(timer->it_clock, nt->expires, next->expires))
+ break;
+ listpos = &next->entry;
+ }
+ list_add(&nt->entry, listpos);
+
+ if (listpos == head) {
+ union cpu_time_count *exp = &nt->expires;
+
+ /*
+ * We are the new earliest-expiring POSIX 1.b timer, hence
+ * need to update expiration cache. Take into account that
+ * for process timers we share expiration cache with itimers
+ * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
+ */
+
+ switch (POSIX_CLOCK_WHICH(timer->it_clock)) {
+ case POSIX_CLOCK_PROF:
+ if (expires_gt(cputime_expires->prof_exp, exp->cpu))
+ cputime_expires->prof_exp = exp->cpu;
+ break;
+ case POSIX_CLOCK_VIRT:
+ if (expires_gt(cputime_expires->virt_exp, exp->cpu))
+ cputime_expires->virt_exp = exp->cpu;
+ break;
+ case POSIX_CLOCK_SCHED:
+ if (cputime_expires->sched_exp == 0 ||
+ cputime_expires->sched_exp > exp->sched)
+ cputime_expires->sched_exp = exp->sched;
+ break;
+ }
+ }
+}
+
+/*
+ * The timer is locked, fire it and arrange for its reload.
+ */
+static void cpu_timer_fire(struct k_itimer *timer)
+{
+ if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
+ /*
+ * User don't want any signal.
+ */
+ timer->it.cpu.expires.sched = 0;
+ } else if (unlikely(timer->sigq == NULL)) {
+ /*
+ * This a special case for clock_nanosleep,
+ * not a normal timer from sys_timer_create.
+ */
+ wake_up_process(timer->it_process);
+ timer->it.cpu.expires.sched = 0;
+ } else if (timer->it.cpu.incr.sched == 0) {
+ /*
+ * One-shot timer. Clear it as soon as it's fired.
+ */
+ posix_timer_event(timer, 0);
+ timer->it.cpu.expires.sched = 0;
+ } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
+ /*
+ * The signal did not get queued because the signal
+ * was ignored, so we won't get any callback to
+ * reload the timer. But we need to keep it
+ * ticking in case the signal is deliverable next time.
+ */
+ posix_cpu_timer_schedule(timer);
+ }
+}
+
+/*
+ * Sample a process (thread group) timer for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ */
+static int cpu_timer_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputimer(p, &cputime);
+ switch (POSIX_CLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case POSIX_CLOCK_PROF:
+ cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+ break;
+ case POSIX_CLOCK_VIRT:
+ cpu->cpu = cputime.utime;
+ break;
+ case POSIX_CLOCK_SCHED:
+ cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Guts of sys_timer_settime for CPU timers.
+ * This is called with the timer locked and interrupts disabled.
+ * If we return TIMER_RETRY, it's necessary to release the timer's lock
+ * and try again. (This happens when the timer is in the middle of firing.)
+ */
+int posix_cpu_timer_set(struct k_itimer *timer, int flags,
+ struct itimerspec *new, struct itimerspec *old)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ union cpu_time_count old_expires, new_expires, old_incr, val;
+ int ret;
+
+ if (unlikely(p == NULL)) {
+ /*
+ * Timer refers to a dead task's clock.
+ */
+ return -ESRCH;
+ }
+
+ new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
+
+ read_lock(&tasklist_lock);
+ /*
+ * We need the tasklist_lock to protect against reaping that
+ * clears p->sighand. If p has just been reaped, we can no
+ * longer get any information about it at all.
+ */
+ if (unlikely(p->sighand == NULL)) {
+ read_unlock(&tasklist_lock);
+ put_task_struct(p);
+ timer->it.cpu.task = NULL;
+ return -ESRCH;
+ }
+
+ /*
+ * Disarm any old timer after extracting its expiry time.
+ */
+ BUG_ON(!irqs_disabled());
+
+ ret = 0;
+ old_incr = timer->it.cpu.incr;
+ spin_lock(&p->sighand->siglock);
+ old_expires = timer->it.cpu.expires;
+ if (unlikely(timer->it.cpu.firing)) {
+ timer->it.cpu.firing = -1;
+ ret = TIMER_RETRY;
+ } else
+ list_del_init(&timer->it.cpu.entry);
+
+ /*
+ * We need to sample the current value to convert the new
+ * value from to relative and absolute, and to convert the
+ * old value from absolute to relative. To set a process
+ * timer, we need a sample to balance the thread expiry
+ * times (in arm_timer). With an absolute time, we must
+ * check if it's already passed. In short, we need a sample.
+ */
+ if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &val);
+ } else {
+ cpu_timer_sample_group(timer->it_clock, p, &val);
+ }
+
+ if (old) {
+ if (old_expires.sched == 0) {
+ old->it_value.tv_sec = 0;
+ old->it_value.tv_nsec = 0;
+ } else {
+ /*
+ * Update the timer in case it has
+ * overrun already. If it has,
+ * we'll report it as having overrun
+ * and with the next reloaded timer
+ * already ticking, though we are
+ * swallowing that pending
+ * notification here to install the
+ * new setting.
+ */
+ bump_cpu_timer(timer, val);
+ if (cpu_time_before(timer->it_clock, val,
+ timer->it.cpu.expires)) {
+ old_expires = cpu_time_sub(
+ timer->it_clock,
+ timer->it.cpu.expires, val);
+ sample_to_timespec(timer->it_clock,
+ old_expires,
+ &old->it_value);
+ } else {
+ old->it_value.tv_nsec = 1;
+ old->it_value.tv_sec = 0;
+ }
+ }
+ }
+
+ if (unlikely(ret)) {
+ /*
+ * We are colliding with the timer actually firing.
+ * Punt after filling in the timer's old value, and
+ * disable this firing since we are already reporting
+ * it as an overrun (thanks to bump_cpu_timer above).
+ */
+ spin_unlock(&p->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ goto out;
+ }
+
+ if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
+ cpu_time_add(timer->it_clock, &new_expires, val);
+ }
+
+ /*
+ * Install the new expiry time (or zero).
+ * For a timer with no notification action, we don't actually
+ * arm the timer (we'll just fake it for timer_gettime).
+ */
+ timer->it.cpu.expires = new_expires;
+ if (new_expires.sched != 0 &&
+ cpu_time_before(timer->it_clock, val, new_expires)) {
+ arm_timer(timer);
+ }
+
+ spin_unlock(&p->sighand->siglock);
+ read_unlock(&tasklist_lock);
+
+ /*
+ * Install the new reload setting, and
+ * set up the signal and overrun bookkeeping.
+ */
+ timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
+ &new->it_interval);
+
+ /*
+ * This acts as a modification timestamp for the timer,
+ * so any automatic reload attempt will punt on seeing
+ * that we have reset the timer manually.
+ */
+ timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
+ ~REQUEUE_PENDING;
+ timer->it_overrun_last = 0;
+ timer->it_overrun = -1;
+
+ if (new_expires.sched != 0 &&
+ !cpu_time_before(timer->it_clock, val, new_expires)) {
+ /*
+ * The designated time already passed, so we notify
+ * immediately, even if the thread never runs to
+ * accumulate more time on this clock.
+ */
+ cpu_timer_fire(timer);
+ }
+
+ ret = 0;
+ out:
+ if (old) {
+ sample_to_timespec(timer->it_clock,
+ old_incr, &old->it_interval);
+ }
+ return ret;
+}
+
+void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
+{
+ union cpu_time_count now;
+ struct task_struct *p = timer->it.cpu.task;
+ int clear_dead;
+
+ /*
+ * Easy part: convert the reload time.
+ */
+ sample_to_timespec(timer->it_clock,
+ timer->it.cpu.incr, &itp->it_interval);
+
+ if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */
+ itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
+ return;
+ }
+
+ if (unlikely(p == NULL)) {
+ /*
+ * This task already died and the timer will never fire.
+ * In this case, expires is actually the dead value.
+ */
+ dead:
+ sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
+ &itp->it_value);
+ return;
+ }
+
+ /*
+ * Sample the clock to take the difference with the expiry time.
+ */
+ if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &now);
+ clear_dead = p->exit_state;
+ } else {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->sighand == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ * Call the timer disarmed, nothing else to do.
+ */
+ put_task_struct(p);
+ timer->it.cpu.task = NULL;
+ timer->it.cpu.expires.sched = 0;
+ read_unlock(&tasklist_lock);
+ goto dead;
+ } else {
+ cpu_timer_sample_group(timer->it_clock, p, &now);
+ clear_dead = (unlikely(p->exit_state) &&
+ thread_group_empty(p));
+ }
+ read_unlock(&tasklist_lock);
+ }
+
+ if (unlikely(clear_dead)) {
+ /*
+ * We've noticed that the thread is dead, but
+ * not yet reaped. Take this opportunity to
+ * drop our task ref.
+ */
+ clear_dead_task(timer, now);
+ goto dead;
+ }
+
+ if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
+ sample_to_timespec(timer->it_clock,
+ cpu_time_sub(timer->it_clock,
+ timer->it.cpu.expires, now),
+ &itp->it_value);
+ } else {
+ /*
+ * The timer should have expired already, but the firing
+ * hasn't taken place yet. Say it's just about to expire.
+ */
+ itp->it_value.tv_nsec = 1;
+ itp->it_value.tv_sec = 0;
+ }
+}
+
+/*
+ * Check for any per-thread CPU timers that have fired and move them off
+ * the tsk->cpu_timers[N] list onto the firing list. Here we update the
+ * tsk->it_*_expires values to reflect the remaining thread CPU timers.
+ */
+static void check_thread_timers(struct task_struct *tsk,
+ struct list_head *firing)
+{
+ int maxfire;
+ struct list_head *timers = tsk->cpu_timers;
+ struct signal_struct *const sig = tsk->signal;
+ unsigned long soft;
+
+ maxfire = 20;
+ tsk->cputime_expires.prof_exp = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
+ tsk->cputime_expires.prof_exp = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ maxfire = 20;
+ tsk->cputime_expires.virt_exp = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
+ tsk->cputime_expires.virt_exp = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ maxfire = 20;
+ tsk->cputime_expires.sched_exp = 0;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
+ tsk->cputime_expires.sched_exp = t->expires.sched;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ /*
+ * Check for the special case thread timers.
+ */
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
+ if (soft != RLIM_INFINITY) {
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
+
+ if (hard != RLIM_INFINITY &&
+ tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
+ /*
+ * At the hard limit, we just die.
+ * No need to calculate anything else now.
+ */
+ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ return;
+ }
+ if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
+ /*
+ * At the soft limit, send a SIGXCPU every second.
+ */
+ if (soft < hard) {
+ soft += USEC_PER_SEC;
+ sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
+ }
+ printk(KERN_INFO
+ "RT Watchdog Timeout: %s[%d]\n",
+ tsk->comm, task_pid_nr(tsk));
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ }
+ }
+}
+
+static void stop_process_timers(struct signal_struct *sig)
+{
+ struct thread_group_cputimer *cputimer = &sig->cputimer;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cputimer->lock, flags);
+ cputimer->running = 0;
+ spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+ cputime_t *expires, cputime_t cur_time, int signo)
+{
+ if (cputime_eq(it->expires, cputime_zero))
+ return;
+
+ if (cputime_ge(cur_time, it->expires)) {
+ if (!cputime_eq(it->incr, cputime_zero)) {
+ it->expires = cputime_add(it->expires, it->incr);
+ it->error += it->incr_error;
+ if (it->error >= onecputick) {
+ it->expires = cputime_sub(it->expires,
+ cputime_one_jiffy);
+ it->error -= onecputick;
+ }
+ } else {
+ it->expires = cputime_zero;
+ }
+
+ trace_itimer_expire(signo == SIGPROF ?
+ ITIMER_PROF : ITIMER_VIRTUAL,
+ tsk->signal->leader_pid, cur_time);
+ __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+ }
+
+ if (!cputime_eq(it->expires, cputime_zero) &&
+ (cputime_eq(*expires, cputime_zero) ||
+ cputime_lt(it->expires, *expires))) {
+ *expires = it->expires;
+ }
+}
+
+/**
+ * task_cputime_zero - Check a task_cputime struct for all zero fields.
+ *
+ * @cputime: The struct to compare.
+ *
+ * Checks @cputime to see if all fields are zero. Returns true if all fields
+ * are zero, false if any field is nonzero.
+ */
+static inline int task_cputime_zero(const struct task_cputime *cputime)
+{
+ if (cputime_eq(cputime->utime, cputime_zero) &&
+ cputime_eq(cputime->stime, cputime_zero) &&
+ cputime->sum_exec_runtime == 0)
+ return 1;
+ return 0;
+}
+
+/*
+ * Check for any per-thread CPU timers that have fired and move them
+ * off the tsk->*_timers list onto the firing list. Per-thread timers
+ * have already been taken off.
+ */
+static void check_process_timers(struct task_struct *tsk,
+ struct list_head *firing)
+{
+ int maxfire;
+ struct signal_struct *const sig = tsk->signal;
+ cputime_t utime, ptime, virt_expires, prof_expires;
+ unsigned long long sum_sched_runtime, sched_expires;
+ struct list_head *timers = sig->cpu_timers;
+ struct task_cputime cputime;
+ unsigned long soft;
+
+ /*
+ * Collect the current process totals.
+ */
+ thread_group_cputimer(tsk, &cputime);
+ utime = cputime.utime;
+ ptime = cputime_add(utime, cputime.stime);
+ sum_sched_runtime = cputime.sum_exec_runtime;
+ maxfire = 20;
+ prof_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *tl = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
+ prof_expires = tl->expires.cpu;
+ break;
+ }
+ tl->firing = 1;
+ list_move_tail(&tl->entry, firing);
+ }
+
+ ++timers;
+ maxfire = 20;
+ virt_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *tl = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
+ virt_expires = tl->expires.cpu;
+ break;
+ }
+ tl->firing = 1;
+ list_move_tail(&tl->entry, firing);
+ }
+
+ ++timers;
+ maxfire = 20;
+ sched_expires = 0;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *tl = list_first_entry(timers,
+ struct cpu_timer_list,
+ entry);
+ if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
+ sched_expires = tl->expires.sched;
+ break;
+ }
+ tl->firing = 1;
+ list_move_tail(&tl->entry, firing);
+ }
+
+ /*
+ * Check for the special case process timers.
+ */
+ check_cpu_itimer(tsk, &sig->it[POSIX_CLOCK_PROF], &prof_expires, ptime,
+ SIGPROF);
+ check_cpu_itimer(tsk, &sig->it[POSIX_CLOCK_VIRT], &virt_expires, utime,
+ SIGVTALRM);
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+ if (soft != RLIM_INFINITY) {
+ unsigned long psecs = cputime_to_secs(ptime);
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
+ cputime_t x;
+ if (psecs >= hard) {
+ /*
+ * At the hard limit, we just die.
+ * No need to calculate anything else now.
+ */
+ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ return;
+ }
+ if (psecs >= soft) {
+ /*
+ * At the soft limit, send a SIGXCPU every second.
+ */
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ if (soft < hard) {
+ soft++;
+ sig->rlim[RLIMIT_CPU].rlim_cur = soft;
+ }
+ }
+ x = secs_to_cputime(soft);
+ if (cputime_eq(prof_expires, cputime_zero) ||
+ cputime_lt(x, prof_expires)) {
+ prof_expires = x;
+ }
+ }
+
+ sig->cputime_expires.prof_exp = prof_expires;
+ sig->cputime_expires.virt_exp = virt_expires;
+ sig->cputime_expires.sched_exp = sched_expires;
+ if (task_cputime_zero(&sig->cputime_expires))
+ stop_process_timers(sig);
+}
+
+/*
+ * This is called from the signal code (via do_schedule_next_timer)
+ * when the last timer signal was delivered and we have to reload the timer.
+ */
+void posix_cpu_timer_schedule(struct k_itimer *timer)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ union cpu_time_count now;
+
+ if (unlikely(p == NULL))
+ /*
+ * The task was cleaned up already, no future firings.
+ */
+ goto out;
+
+ /*
+ * Fetch the current sample and update the timer's expiry time.
+ */
+ if (POSIX_CLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &now);
+ bump_cpu_timer(timer, now);
+ if (unlikely(p->exit_state)) {
+ clear_dead_task(timer, now);
+ goto out;
+ }
+ read_lock(&tasklist_lock); /* arm_timer needs it. */
+ spin_lock(&p->sighand->siglock);
+ } else {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->sighand == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ */
+ put_task_struct(p);
+ timer->it.cpu.task = p = NULL;
+ timer->it.cpu.expires.sched = 0;
+ goto out_unlock;
+ } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
+ /*
+ * We've noticed that the thread is dead, but
+ * not yet reaped. Take this opportunity to
+ * drop our task ref.
+ */
+ clear_dead_task(timer, now);
+ goto out_unlock;
+ }
+ spin_lock(&p->sighand->siglock);
+ cpu_timer_sample_group(timer->it_clock, p, &now);
+ bump_cpu_timer(timer, now);
+ /* Leave the tasklist_lock locked for the call below. */
+ }
+
+ /*
+ * Now re-arm for the new expiry time.
+ */
+ BUG_ON(!irqs_disabled());
+ arm_timer(timer);
+ spin_unlock(&p->sighand->siglock);
+
+out_unlock:
+ read_unlock(&tasklist_lock);
+
+out:
+ timer->it_overrun_last = timer->it_overrun;
+ timer->it_overrun = -1;
+ ++timer->it_requeue_pending;
+}
+
+/**
+ * task_cputime_expired - Compare two task_cputime entities.
+ *
+ * @sample: The task_cputime structure to be checked for expiration.
+ * @expires: Expiration times, against which @sample will be checked.
+ *
+ * Checks @sample against @expires to see if any field of @sample has expired.
+ * Returns true if any field of the former is greater than the corresponding
+ * field of the latter if the latter field is set. Otherwise returns false.
+ */
+static inline int task_cputime_expired(const struct task_cputime *sample,
+ const struct task_cputime *expires)
+{
+ if (!cputime_eq(expires->utime, cputime_zero) &&
+ cputime_ge(sample->utime, expires->utime))
+ return 1;
+ if (!cputime_eq(expires->stime, cputime_zero) &&
+ cputime_ge(cputime_add(sample->utime, sample->stime),
+ expires->stime))
+ return 1;
+ if (expires->sum_exec_runtime != 0 &&
+ sample->sum_exec_runtime >= expires->sum_exec_runtime)
+ return 1;
+ return 0;
+}
+
+/**
+ * fastpath_timer_check - POSIX CPU timers fast path.
+ *
+ * @tsk: The task (thread) being checked.
+ *
+ * Check the task and thread group timers. If both are zero (there are no
+ * timers set) return false. Otherwise snapshot the task and thread group
+ * timers and compare them with the corresponding expiration times. Return
+ * true if a timer has expired, else return false.
+ */
+static inline int fastpath_timer_check(struct task_struct *tsk)
+{
+ struct signal_struct *sig;
+
+ /* tsk == current, ensure it is safe to use ->signal/sighand */
+ if (unlikely(tsk->exit_state))
+ return 0;
+
+ if (!task_cputime_zero(&tsk->cputime_expires)) {
+ struct task_cputime task_sample = {
+ .utime = tsk->utime,
+ .stime = tsk->stime,
+ .sum_exec_runtime = tsk->se.sum_exec_runtime
+ };
+
+ if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
+ return 1;
+ }
+
+ sig = tsk->signal;
+ if (sig->cputimer.running) {
+ struct task_cputime group_sample;
+
+ thread_group_cputimer(tsk, &group_sample);
+ if (task_cputime_expired(&group_sample, &sig->cputime_expires))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * This is called from the timer interrupt handler. The irq handler has
+ * already updated our counts. We need to check if any timers fire now.
+ * Interrupts are disabled.
+ */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ LIST_HEAD(firing);
+ struct k_itimer *timer, *next;
+
+ BUG_ON(!irqs_disabled());
+
+ /*
+ * The fast path checks that there are no expired thread or thread
+ * group timers. If that's so, just return.
+ */
+ if (!fastpath_timer_check(tsk))
+ return;
+
+ spin_lock(&tsk->sighand->siglock);
+ /*
+ * Here we take off tsk->signal->cpu_timers[N] and
+ * tsk->cpu_timers[N] all the timers that are firing, and
+ * put them on the firing list.
+ */
+ check_thread_timers(tsk, &firing);
+ /*
+ * If there are any active process wide timers (POSIX 1.b, itimers,
+ * RLIMIT_CPU) cputimer must be running.
+ */
+ if (tsk->signal->cputimer.running)
+ check_process_timers(tsk, &firing);
+
+ /*
+ * We must release these locks before taking any timer's lock.
+ * There is a potential race with timer deletion here, as the
+ * siglock now protects our private firing list. We have set
+ * the firing flag in each timer, so that a deletion attempt
+ * that gets the timer lock before we do will give it up and
+ * spin until we've taken care of that timer below.
+ */
+ spin_unlock(&tsk->sighand->siglock);
+
+ /*
+ * Now that all the timers on our list have the firing flag,
+ * noone will touch their list entries but us. We'll take
+ * each timer's lock before clearing its firing flag, so no
+ * timer call will interfere.
+ */
+ list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
+ int cpu_firing;
+
+ spin_lock(&timer->it_lock);
+ list_del_init(&timer->it.cpu.entry);
+ cpu_firing = timer->it.cpu.firing;
+ timer->it.cpu.firing = 0;
+ /*
+ * The firing flag is -1 if we collided with a reset
+ * of the timer, which already reported this
+ * almost-firing as an overrun. So don't generate an event.
+ */
+ if (likely(cpu_firing >= 0))
+ cpu_timer_fire(timer);
+ spin_unlock(&timer->it_lock);
+ }
+}
+
+/*
+ * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
+ * The tsk->sighand->siglock must be held by the caller.
+ */
+void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
+ cputime_t *newval, cputime_t *oldval)
+{
+ union cpu_time_count now;
+
+ BUG_ON(clock_idx == POSIX_CLOCK_SCHED);
+ cpu_timer_sample_group(clock_idx, tsk, &now);
+
+ if (oldval) {
+ /*
+ * We are setting itimer. The *oldval is absolute and we update
+ * it to be relative, *newval argument is relative and we update
+ * it to be absolute.
+ */
+ if (!cputime_eq(*oldval, cputime_zero)) {
+ if (cputime_le(*oldval, now.cpu)) {
+ /* Just about to fire. */
+ *oldval = cputime_one_jiffy;
+ } else {
+ *oldval = cputime_sub(*oldval, now.cpu);
+ }
+ }
+
+ if (cputime_eq(*newval, cputime_zero))
+ return;
+ *newval = cputime_add(*newval, now.cpu);
+ }
+
+ /*
+ * Update expiration cache if we are the earliest timer, or eventually
+ * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
+ */
+ switch (clock_idx) {
+ case POSIX_CLOCK_PROF:
+ if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
+ tsk->signal->cputime_expires.prof_exp = *newval;
+ break;
+ case POSIX_CLOCK_VIRT:
+ if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
+ tsk->signal->cputime_expires.virt_exp = *newval;
+ break;
+ }
+}
+
+static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct itimerspec *it)
+{
+ struct k_itimer timer;
+ int error;
+
+ /*
+ * Set up a temporary timer and then wait for it to go off.
+ */
+ memset(&timer, 0, sizeof timer);
+ spin_lock_init(&timer.it_lock);
+ timer.it_clock = which_clock;
+ timer.it_overrun = -1;
+ error = posix_cpu_timer_create(&timer);
+ timer.it_process = current;
+ if (!error) {
+ static struct itimerspec zero_it;
+
+ memset(it, 0, sizeof *it);
+ it->it_value = *rqtp;
+
+ spin_lock_irq(&timer.it_lock);
+ error = posix_cpu_timer_set(&timer, flags, it, NULL);
+ if (error) {
+ spin_unlock_irq(&timer.it_lock);
+ return error;
+ }
+
+ while (!signal_pending(current)) {
+ if (timer.it.cpu.expires.sched == 0) {
+ /*
+ * Our timer fired and was reset.
+ */
+ spin_unlock_irq(&timer.it_lock);
+ return 0;
+ }
+
+ /*
+ * Block until cpu_timer_fire (or a signal) wakes us.
+ */
+ __set_current_state(TASK_INTERRUPTIBLE);
+ spin_unlock_irq(&timer.it_lock);
+ schedule();
+ spin_lock_irq(&timer.it_lock);
+ }
+
+ /*
+ * We were interrupted by a signal.
+ */
+ sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
+ posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ spin_unlock_irq(&timer.it_lock);
+
+ if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
+ /*
+ * It actually did fire already.
+ */
+ return 0;
+ }
+
+ error = -ERESTART_RESTARTBLOCK;
+ }
+
+ return error;
+}
+
+int posix_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct timespec __user *rmtp)
+{
+ struct restart_block *restart_block =
+ ¤t_thread_info()->restart_block;
+ struct itimerspec it;
+ int error;
+
+ /*
+ * Diagnose required errors first.
+ */
+ if (POSIX_CLOCK_PERTHREAD(which_clock) &&
+ (POSIX_CLOCK_PID(which_clock) == 0 ||
+ POSIX_CLOCK_PID(which_clock) == current->pid))
+ return -EINVAL;
+
+ error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
+
+ if (error == -ERESTART_RESTARTBLOCK) {
+
+ if (flags & TIMER_ABSTIME)
+ return -ERESTARTNOHAND;
+ /*
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->fn = posix_cpu_nsleep_restart;
+ restart_block->arg0 = which_clock;
+ restart_block->arg1 = (unsigned long) rmtp;
+ restart_block->arg2 = rqtp->tv_sec;
+ restart_block->arg3 = rqtp->tv_nsec;
+ }
+ return error;
+}
+
+long posix_cpu_nsleep_restart(struct restart_block *restart_block)
+{
+ clockid_t which_clock = restart_block->arg0;
+ struct timespec __user *rmtp;
+ struct timespec t;
+ struct itimerspec it;
+ int error;
+
+ rmtp = (struct timespec __user *) restart_block->arg1;
+ t.tv_sec = restart_block->arg2;
+ t.tv_nsec = restart_block->arg3;
+
+ restart_block->fn = do_no_restart_syscall;
+ error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
+
+ if (error == -ERESTART_RESTARTBLOCK) {
+ /*
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->fn = posix_cpu_nsleep_restart;
+ restart_block->arg0 = which_clock;
+ restart_block->arg1 = (unsigned long) rmtp;
+ restart_block->arg2 = t.tv_sec;
+ restart_block->arg3 = t.tv_nsec;
+ }
+ return error;
+
+}
+
+
+#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, POSIX_CLOCK_SCHED)
+#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, POSIX_CLOCK_SCHED)
+
+static int process_cpu_clock_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
+}
+static int process_cpu_clock_get(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_get(PROCESS_CLOCK, tp);
+}
+static int process_cpu_timer_create(struct k_itimer *timer)
+{
+ timer->it_clock = PROCESS_CLOCK;
+ return posix_cpu_timer_create(timer);
+}
+static int process_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp,
+ struct timespec __user *rmtp)
+{
+ return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
+}
+static long process_cpu_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+static int thread_cpu_clock_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_getres(THREAD_CLOCK, tp);
+}
+static int thread_cpu_clock_get(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_get(THREAD_CLOCK, tp);
+}
+static int thread_cpu_timer_create(struct k_itimer *timer)
+{
+ timer->it_clock = THREAD_CLOCK;
+ return posix_cpu_timer_create(timer);
+}
+static int thread_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct timespec __user *rmtp)
+{
+ return -EINVAL;
+}
+static long thread_cpu_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+
+static __init int init_posix_cpu_timers(void)
+{
+ struct k_clock cpu_process = {
+ .clock_getres = process_cpu_clock_getres,
+ .clock_get = process_cpu_clock_get,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = process_cpu_timer_create,
+ .nsleep = process_cpu_nsleep,
+ .nsleep_restart = process_cpu_nsleep_restart,
+ };
+ struct k_clock cpu_thread = {
+ .clock_getres = thread_cpu_clock_getres,
+ .clock_get = thread_cpu_clock_get,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = thread_cpu_timer_create,
+ .nsleep = thread_cpu_nsleep,
+ .nsleep_restart = thread_cpu_nsleep_restart,
+ };
+ struct k_clock wall_process = {
+ .clock_getres = process_wall_getres,
+ .clock_get = process_wall_get,
+ .clock_set = wall_clock_set,
+ .timer_create = wall_timer_create,
+ .nsleep = process_wall_nsleep,
+ .nsleep_restart = process_wall_nsleep_restart,
+ };
+ struct k_clock wall_thread = {
+ .clock_getres = thread_wall_getres,
+ .clock_get = thread_wall_get,
+ .clock_set = wall_clock_set,
+ .timer_create = wall_timer_create,
+ .nsleep = thread_wall_nsleep,
+ .nsleep_restart = thread_wall_nsleep_restart,
+ };
+ struct timespec ts;
+
+ register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &cpu_process);
+ register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &cpu_thread);
+ register_posix_clock(CLOCK_PROCESS_WALLTIME_ID, &wall_process);
+ register_posix_clock(CLOCK_THREAD_WALLTIME_ID, &wall_thread);
+
+ cputime_to_timespec(cputime_one_jiffy, &ts);
+ onecputick = ts.tv_nsec;
+ WARN_ON(ts.tv_sec != 0);
+
+ return 0;
+}
+__initcall(init_posix_cpu_timers);
--
1.6.3.3
^ permalink raw reply [flat|nested] 11+ messages in thread