* [PATCH] Adding support of RLIMIT_CPUNS
@ 2017-08-17 19:45 Григорий Резников
2017-08-17 19:49 ` Andrew Morton
2017-08-18 11:46 ` Michal Hocko
0 siblings, 2 replies; 3+ messages in thread
From: Григорий Резников @ 2017-08-17 19:45 UTC (permalink / raw)
To: akpm, linux-kernel
To set time limit for process now we can use RLIMIT_CPU.
However, it has precision up to one second and it can be
too big for some purposes.
This patch adds support of RLIMIT_CPUNS, which works
almost as RLIMIT_CPU, but has nanosecond precision.
At the moment, RLIMIT_CPU and RLIMIT_CPUNS are two
independent values, because I don't see any nice way
for them to be together.
Signed-off-by: Grigory Reznikov <grikukan@mail.ru>
---
fs/proc/base.c | 1 +
include/asm-generic/resource.h | 1 +
include/linux/posix-timers.h | 1 +
include/uapi/asm-generic/resource.h | 4 +++-
kernel/fork.c | 20 +++++++++++++----
kernel/sys.c | 11 ++++++++-
kernel/time/posix-cpu-timers.c | 45 +++++++++++++++++++++++++++++++++----
7 files changed, 73 insertions(+), 10 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 719c2e9..1e3049e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -567,6 +567,7 @@ static const struct limit_names lnames[RLIM_NLIMITS] = {
[RLIMIT_NICE] = {"Max nice priority", NULL},
[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
+ [RLIMIT_CPUNS] = {"Max cpu time", "ns"},
};
/* Display limits for a process */
diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h
index 5e752b9..ec7b0c5 100644
--- a/include/asm-generic/resource.h
+++ b/include/asm-generic/resource.h
@@ -25,6 +25,7 @@
[RLIMIT_NICE] = { 0, 0 }, \
[RLIMIT_RTPRIO] = { 0, 0 }, \
[RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \
+ [RLIMIT_CPUNS] = { RLIM_INFINITY, RLIM_INFINITY }, \
}
#endif
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 62839fd..0e22bde 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -110,6 +110,7 @@ void posix_cpu_timers_exit_group(struct task_struct *task);
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
u64 *newval, u64 *oldval);
+void update_rlimit_cpu_ns(struct task_struct *task, unsigned long rlim_new);
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
void posixtimer_rearm(struct siginfo *info);
diff --git a/include/uapi/asm-generic/resource.h b/include/uapi/asm-generic/resource.h
index c6d10af..a86b2f4 100644
--- a/include/uapi/asm-generic/resource.h
+++ b/include/uapi/asm-generic/resource.h
@@ -45,7 +45,9 @@
0-39 for nice level 19 .. -20 */
#define RLIMIT_RTPRIO 14 /* maximum realtime priority */
#define RLIMIT_RTTIME 15 /* timeout for RT tasks in us */
-#define RLIM_NLIMITS 16
+#define RLIMIT_CPUNS 16 /* CPU time in ns,
+ doesn't depend on RLIMIT_CPU */
+#define RLIM_NLIMITS 17
/*
* SuS says limits have to be unsigned.
diff --git a/kernel/fork.c b/kernel/fork.c
index e075b77..33f9bbf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1348,11 +1348,23 @@ void __cleanup_sighand(struct sighand_struct *sighand)
*/
static void posix_cpu_timers_init_group(struct signal_struct *sig)
{
- unsigned long cpu_limit;
-
+ unsigned long cpu_limit, cpuns_limit, total_limit;
+ /* RLIMIT_CPU timeout, RLIMIT_CPUNS timeout and time
+ * to closest timeout
+ */
+
cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
- if (cpu_limit != RLIM_INFINITY) {
- sig->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
+ cpuns_limit = READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_cur);
+
+ total_limit = RLIM_INFINITY;
+
+ if (cpu_limit != RLIM_INFINITY)
+ total_limit = cpu_limit * NSEC_PER_SEC;
+ if (cpuns_limit != RLIM_INFINITY && cpuns_limit < total_limit)
+ total_limit = cpuns_limit;
+
+ if (total_limit != RLIM_INFINITY) {
+ sig->cputime_expires.prof_exp = total_limit;
sig->cputimer.running = true;
}
diff --git a/kernel/sys.c b/kernel/sys.c
index 2855ee7..539b110 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1504,6 +1504,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
*/
new_rlim->rlim_cur = 1;
}
+ if (resource == RLIMIT_CPUNS && new_rlim->rlim_cur == 0)
+ new_rlim->rlim_cur = NSEC_PER_SEC;
}
if (!retval) {
if (old_rlim)
@@ -1519,10 +1521,17 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
* very long-standing error, and fixing it now risks breakage of
* applications, so we live with it
*/
- if (!retval && new_rlim && resource == RLIMIT_CPU &&
+ if (!retval && new_rlim && resource == RIMIT_CPU &&
new_rlim->rlim_cur != RLIM_INFINITY &&
IS_ENABLED(CONFIG_POSIX_TIMERS))
update_rlimit_cpu(tsk, new_rlim->rlim_cur);
+
+ if (!retval && new_rlim && resource == RLIMIT_CPUNS &&
+ new_rlim->rlim_cur != RLIM_INFINITY &&
+ IS_ENABLED(CONFIG_POSIX_TIMERS))
+ update_rlimit_cpu_ns(tsk, new_rlim->rlim_cur);
+
+
out:
read_unlock(&tasklist_lock);
return retval;
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index a3bd5db..e4830f6 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -19,20 +19,26 @@
static void posix_cpu_timer_rearm(struct k_itimer *timer);
/*
- * Called after updating RLIMIT_CPU to run cpu timer and update
+ * Called after updating RLIMIT_CPUNS 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(struct task_struct *task, unsigned long rlim_new)
+void update_rlimit_cpu_ns(struct task_struct *task, unsigned long rlim_new)
{
- u64 nsecs = rlim_new * NSEC_PER_SEC;
+ u64 nsecs = rlim_new;
spin_lock_irq(&task->sighand->siglock);
set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL);
spin_unlock_irq(&task->sighand->siglock);
}
+/* Same function for RLIMIT_CPU */
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
+{
+ update_rlimit_cpu(task, rlim_new * NSEC_PER_SEC);
+}
+
static int check_clock(const clockid_t which_clock)
{
int error = 0;
@@ -938,6 +944,9 @@ static void check_process_timers(struct task_struct *tsk,
SIGPROF);
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
SIGVTALRM);
+ /*
+ * RLIMIT_CPU check
+ */
soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
if (soft != RLIM_INFINITY) {
unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
@@ -974,7 +983,35 @@ static void check_process_timers(struct task_struct *tsk,
if (!prof_expires || x < prof_expires)
prof_expires = x;
}
-
+ /*
+ * RLIMIT_CPUNS check
+ */
+ soft = READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_cur);
+ if (soft != RLIM_INFINITY) {
+ unsigned long hard =
+ READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_max);
+ if (ptime >= hard) {
+ if (print_fatal_signals) {
+ pr_info("RT Watchdog Timeout (hard): %s[%d]\n",
+ tsk->comm, task_pid_nr(tsk));
+ }
+ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ return;
+ }
+ if (ptime >= soft) {
+ if (print_fatal_signals) {
+ pr_info("CPU Watchdog Timeout (soft): %s[%d]\n",
+ tsk->comm, task_pid_nr(tsk));
+ }
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ if (soft < hard) {
+ soft += NSEC_PER_SEC;
+ sig->rlim[RLIMIT_CPUNS].rlim_cur = soft;
+ }
+ }
+ if (!prof_expires || soft < prof_expires)
+ prof_expires = soft;
+ }
sig->cputime_expires.prof_exp = prof_expires;
sig->cputime_expires.virt_exp = virt_expires;
sig->cputime_expires.sched_exp = sched_expires;
--
2.7.4
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Adding support of RLIMIT_CPUNS
2017-08-17 19:45 [PATCH] Adding support of RLIMIT_CPUNS Григорий Резников
@ 2017-08-17 19:49 ` Andrew Morton
2017-08-18 11:46 ` Michal Hocko
1 sibling, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2017-08-17 19:49 UTC (permalink / raw)
To: Григорий
Резников
Cc: linux-kernel
On Thu, 17 Aug 2017 22:45:45 +0300 ________________ ________________ <grikukan@mail.ru> wrote:
> To set time limit for process now we can use RLIMIT_CPU.
> However, it has precision up to one second and it can be
> too big for some purposes.
>
> This patch adds support of RLIMIT_CPUNS, which works
> almost as RLIMIT_CPU, but has nanosecond precision.
>
> At the moment, RLIMIT_CPU and RLIMIT_CPUNS are two
> independent values, because I don't see any nice way
> for them to be together.
We'll need to hear much, much more about "for some purposes", please.
What are the use cases, why are they important, who will benefit from
this and in what ways, etc? How will this change benefit our users?
Presenting this material is critical, so please spend time over it.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Adding support of RLIMIT_CPUNS
2017-08-17 19:45 [PATCH] Adding support of RLIMIT_CPUNS Григорий Резников
2017-08-17 19:49 ` Andrew Morton
@ 2017-08-18 11:46 ` Michal Hocko
1 sibling, 0 replies; 3+ messages in thread
From: Michal Hocko @ 2017-08-18 11:46 UTC (permalink / raw)
To: Григорий
Резников
Cc: akpm, linux-kernel, linux-api
Appart from Andrew said about the usecase make sure to CC linux-api for
any user visible interface change.
On Thu 17-08-17 22:45:45, Григорий Резников wrote:
> To set time limit for process now we can use RLIMIT_CPU.
> However, it has precision up to one second and it can be
> too big for some purposes.
>
> This patch adds support of RLIMIT_CPUNS, which works
> almost as RLIMIT_CPU, but has nanosecond precision.
>
> At the moment, RLIMIT_CPU and RLIMIT_CPUNS are two
> independent values, because I don't see any nice way
> for them to be together.
>
> Signed-off-by: Grigory Reznikov <grikukan@mail.ru>
> ---
> fs/proc/base.c | 1 +
> include/asm-generic/resource.h | 1 +
> include/linux/posix-timers.h | 1 +
> include/uapi/asm-generic/resource.h | 4 +++-
> kernel/fork.c | 20 +++++++++++++----
> kernel/sys.c | 11 ++++++++-
> kernel/time/posix-cpu-timers.c | 45 +++++++++++++++++++++++++++++++++----
> 7 files changed, 73 insertions(+), 10 deletions(-)
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 719c2e9..1e3049e 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -567,6 +567,7 @@ static const struct limit_names lnames[RLIM_NLIMITS] = {
> [RLIMIT_NICE] = {"Max nice priority", NULL},
> [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
> [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
> + [RLIMIT_CPUNS] = {"Max cpu time", "ns"},
> };
>
> /* Display limits for a process */
> diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h
> index 5e752b9..ec7b0c5 100644
> --- a/include/asm-generic/resource.h
> +++ b/include/asm-generic/resource.h
> @@ -25,6 +25,7 @@
> [RLIMIT_NICE] = { 0, 0 }, \
> [RLIMIT_RTPRIO] = { 0, 0 }, \
> [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \
> + [RLIMIT_CPUNS] = { RLIM_INFINITY, RLIM_INFINITY }, \
> }
>
> #endif
> diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
> index 62839fd..0e22bde 100644
> --- a/include/linux/posix-timers.h
> +++ b/include/linux/posix-timers.h
> @@ -110,6 +110,7 @@ void posix_cpu_timers_exit_group(struct task_struct *task);
> void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
> u64 *newval, u64 *oldval);
>
> +void update_rlimit_cpu_ns(struct task_struct *task, unsigned long rlim_new);
> void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
>
> void posixtimer_rearm(struct siginfo *info);
> diff --git a/include/uapi/asm-generic/resource.h b/include/uapi/asm-generic/resource.h
> index c6d10af..a86b2f4 100644
> --- a/include/uapi/asm-generic/resource.h
> +++ b/include/uapi/asm-generic/resource.h
> @@ -45,7 +45,9 @@
> 0-39 for nice level 19 .. -20 */
> #define RLIMIT_RTPRIO 14 /* maximum realtime priority */
> #define RLIMIT_RTTIME 15 /* timeout for RT tasks in us */
> -#define RLIM_NLIMITS 16
> +#define RLIMIT_CPUNS 16 /* CPU time in ns,
> + doesn't depend on RLIMIT_CPU */
> +#define RLIM_NLIMITS 17
>
> /*
> * SuS says limits have to be unsigned.
> diff --git a/kernel/fork.c b/kernel/fork.c
> index e075b77..33f9bbf 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1348,11 +1348,23 @@ void __cleanup_sighand(struct sighand_struct *sighand)
> */
> static void posix_cpu_timers_init_group(struct signal_struct *sig)
> {
> - unsigned long cpu_limit;
> -
> + unsigned long cpu_limit, cpuns_limit, total_limit;
> + /* RLIMIT_CPU timeout, RLIMIT_CPUNS timeout and time
> + * to closest timeout
> + */
> +
> cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
> - if (cpu_limit != RLIM_INFINITY) {
> - sig->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
> + cpuns_limit = READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_cur);
> +
> + total_limit = RLIM_INFINITY;
> +
> + if (cpu_limit != RLIM_INFINITY)
> + total_limit = cpu_limit * NSEC_PER_SEC;
> + if (cpuns_limit != RLIM_INFINITY && cpuns_limit < total_limit)
> + total_limit = cpuns_limit;
> +
> + if (total_limit != RLIM_INFINITY) {
> + sig->cputime_expires.prof_exp = total_limit;
> sig->cputimer.running = true;
> }
>
> diff --git a/kernel/sys.c b/kernel/sys.c
> index 2855ee7..539b110 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -1504,6 +1504,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
> */
> new_rlim->rlim_cur = 1;
> }
> + if (resource == RLIMIT_CPUNS && new_rlim->rlim_cur == 0)
> + new_rlim->rlim_cur = NSEC_PER_SEC;
> }
> if (!retval) {
> if (old_rlim)
> @@ -1519,10 +1521,17 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
> * very long-standing error, and fixing it now risks breakage of
> * applications, so we live with it
> */
> - if (!retval && new_rlim && resource == RLIMIT_CPU &&
> + if (!retval && new_rlim && resource == RIMIT_CPU &&
> new_rlim->rlim_cur != RLIM_INFINITY &&
> IS_ENABLED(CONFIG_POSIX_TIMERS))
> update_rlimit_cpu(tsk, new_rlim->rlim_cur);
> +
> + if (!retval && new_rlim && resource == RLIMIT_CPUNS &&
> + new_rlim->rlim_cur != RLIM_INFINITY &&
> + IS_ENABLED(CONFIG_POSIX_TIMERS))
> + update_rlimit_cpu_ns(tsk, new_rlim->rlim_cur);
> +
> +
> out:
> read_unlock(&tasklist_lock);
> return retval;
> diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
> index a3bd5db..e4830f6 100644
> --- a/kernel/time/posix-cpu-timers.c
> +++ b/kernel/time/posix-cpu-timers.c
> @@ -19,20 +19,26 @@
> static void posix_cpu_timer_rearm(struct k_itimer *timer);
>
> /*
> - * Called after updating RLIMIT_CPU to run cpu timer and update
> + * Called after updating RLIMIT_CPUNS 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(struct task_struct *task, unsigned long rlim_new)
> +void update_rlimit_cpu_ns(struct task_struct *task, unsigned long rlim_new)
> {
> - u64 nsecs = rlim_new * NSEC_PER_SEC;
> + u64 nsecs = rlim_new;
>
> spin_lock_irq(&task->sighand->siglock);
> set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL);
> spin_unlock_irq(&task->sighand->siglock);
> }
>
> +/* Same function for RLIMIT_CPU */
> +void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
> +{
> + update_rlimit_cpu(task, rlim_new * NSEC_PER_SEC);
> +}
> +
> static int check_clock(const clockid_t which_clock)
> {
> int error = 0;
> @@ -938,6 +944,9 @@ static void check_process_timers(struct task_struct *tsk,
> SIGPROF);
> check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
> SIGVTALRM);
> + /*
> + * RLIMIT_CPU check
> + */
> soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
> if (soft != RLIM_INFINITY) {
> unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
> @@ -974,7 +983,35 @@ static void check_process_timers(struct task_struct *tsk,
> if (!prof_expires || x < prof_expires)
> prof_expires = x;
> }
> -
> + /*
> + * RLIMIT_CPUNS check
> + */
> + soft = READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_cur);
> + if (soft != RLIM_INFINITY) {
> + unsigned long hard =
> + READ_ONCE(sig->rlim[RLIMIT_CPUNS].rlim_max);
> + if (ptime >= hard) {
> + if (print_fatal_signals) {
> + pr_info("RT Watchdog Timeout (hard): %s[%d]\n",
> + tsk->comm, task_pid_nr(tsk));
> + }
> + __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
> + return;
> + }
> + if (ptime >= soft) {
> + if (print_fatal_signals) {
> + pr_info("CPU Watchdog Timeout (soft): %s[%d]\n",
> + tsk->comm, task_pid_nr(tsk));
> + }
> + __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
> + if (soft < hard) {
> + soft += NSEC_PER_SEC;
> + sig->rlim[RLIMIT_CPUNS].rlim_cur = soft;
> + }
> + }
> + if (!prof_expires || soft < prof_expires)
> + prof_expires = soft;
> + }
> sig->cputime_expires.prof_exp = prof_expires;
> sig->cputime_expires.virt_exp = virt_expires;
> sig->cputime_expires.sched_exp = sched_expires;
> --
> 2.7.4
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-08-18 11:46 UTC | newest]
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2017-08-17 19:49 ` Andrew Morton
2017-08-18 11:46 ` Michal Hocko
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