From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@elte.hu>,
Carsten Emde <carsten.emde@osadl.org>,
Carsten Emde <C.Emde@osadl.org>
Subject: [patch-rt 3/4] ftrace: display real preempt_count in ftracer
Date: Wed, 28 Jan 2009 21:29:16 -0000 [thread overview]
Message-ID: <20090128212709.293895401@linutronix.de> (raw)
In-Reply-To: <20090128211912.300823284@linutronix.de>
[-- Attachment #1: ftrace-correctly-display-preempt-count-in-ftracer.patch --]
[-- Type: text/plain, Size: 13504 bytes --]
ftrace determined the preempt_count after preemption was disabled
instead of the original preemption count.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/trace/trace.c | 54 +++++++++++++++++++-------------------
kernel/trace/trace.h | 3 +-
kernel/trace/trace_hist.c | 2 -
kernel/trace/trace_irqsoff.c | 13 +++++----
kernel/trace/trace_sched_wakeup.c | 9 ++++--
5 files changed, 45 insertions(+), 36 deletions(-)
Index: linux-2.6.26/kernel/trace/trace.c
===================================================================
--- linux-2.6.26.orig/kernel/trace/trace.c
+++ linux-2.6.26/kernel/trace/trace.c
@@ -833,12 +833,10 @@ tracing_get_trace_entry(struct trace_arr
}
static inline void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+ unsigned long pc)
{
struct task_struct *tsk = current;
- unsigned long pc;
-
- pc = preempt_count();
entry->field.preempt_count = pc & 0xff;
entry->field.pid = (tsk) ? tsk->pid : 0;
@@ -852,7 +850,8 @@ tracing_generic_entry_update(struct trac
void
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip, unsigned long flags)
+ unsigned long ip, unsigned long parent_ip, unsigned long flags,
+ unsigned long pc)
{
struct trace_entry *entry;
unsigned long irq_flags;
@@ -860,7 +859,7 @@ trace_function(struct trace_array *tr, s
raw_local_irq_save(irq_flags);
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, pc);
entry->type = TRACE_FN;
entry->field.fn.ip = ip;
entry->field.fn.parent_ip = parent_ip;
@@ -873,7 +872,8 @@ ftrace(struct trace_array *tr, struct tr
unsigned long ip, unsigned long parent_ip, unsigned long flags)
{
if (likely(!atomic_read(&data->disabled)))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags,
+ preempt_count());
}
#ifdef CONFIG_MMIOTRACE
@@ -887,7 +887,7 @@ void __trace_mmiotrace_rw(struct trace_a
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
+ tracing_generic_entry_update(entry, 0, preempt_count());
entry->type = TRACE_MMIO_RW;
entry->field.mmiorw = *rw;
@@ -907,7 +907,7 @@ void __trace_mmiotrace_map(struct trace_
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
+ tracing_generic_entry_update(entry, 0, preempt_count());
entry->type = TRACE_MMIO_MAP;
entry->field.mmiomap = *map;
@@ -930,7 +930,7 @@ void __trace_stack(struct trace_array *t
return;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_STACK;
memset(&entry->field.stack, 0, sizeof(entry->field.stack));
@@ -955,7 +955,7 @@ __trace_special(void *__tr, void *__data
raw_local_irq_save(irq_flags);
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, 0);
+ tracing_generic_entry_update(entry, 0, preempt_count());
entry->type = TRACE_SPECIAL;
entry->field.special.arg1 = arg1;
entry->field.special.arg2 = arg2;
@@ -980,7 +980,7 @@ tracing_sched_switch_trace(struct trace_
raw_local_irq_save(irq_flags);
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_CTX;
entry->field.ctx.prev_pid = prev->pid;
entry->field.ctx.prev_prio = prev->prio;
@@ -1007,7 +1007,7 @@ tracing_sched_wakeup_trace(struct trace_
raw_local_irq_save(irq_flags);
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_WAKE;
entry->field.ctx.prev_pid = curr->pid;
entry->field.ctx.prev_prio = curr->prio;
@@ -1057,7 +1057,7 @@ void tracing_event_irq(struct trace_arra
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_IRQ;
entry->field.irq.ip = ip;
entry->field.irq.irq = irq;
@@ -1076,7 +1076,7 @@ void tracing_event_fault(struct trace_ar
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_FAULT;
entry->field.fault.ip = ip;
entry->field.fault.ret_ip = retip;
@@ -1093,7 +1093,7 @@ void tracing_event_timer_set(struct trac
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_TIMER_SET;
entry->field.timer.ip = ip;
entry->field.timer.expire = *expires;
@@ -1109,7 +1109,7 @@ void tracing_event_program_event(struct
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_PROGRAM_EVENT;
entry->field.program.ip = ip;
entry->field.program.expire = *expires;
@@ -1126,7 +1126,7 @@ void tracing_event_resched_task(struct t
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_RESCHED_TASK;
entry->field.task.ip = ip;
entry->field.task.prio = p->prio;
@@ -1143,7 +1143,7 @@ void tracing_event_timer_triggered(struc
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_TIMER_TRIG;
entry->field.timer.ip = ip;
entry->field.timer.expire = *expired;
@@ -1159,7 +1159,7 @@ void tracing_event_timestamp(struct trac
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_TIMESTAMP;
entry->field.timestamp.ip = ip;
entry->field.timestamp.now = *now;
@@ -1175,7 +1175,7 @@ void tracing_event_task_activate(struct
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_TASK_ACT;
entry->field.task.ip = ip;
entry->field.task.pid = p->pid;
@@ -1193,7 +1193,7 @@ void tracing_event_task_deactivate(struc
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_TASK_DEACT;
entry->field.task.ip = ip;
entry->field.task.pid = p->pid;
@@ -1213,7 +1213,7 @@ void tracing_event_syscall(struct trace_
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_SYSCALL;
entry->field.syscall.ip = ip;
entry->field.syscall.nr = nr;
@@ -1231,7 +1231,7 @@ void tracing_event_sysret(struct trace_a
struct trace_entry *entry;
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_SYSRET;
entry->field.sysret.ip = ip;
entry->field.sysret.ret = ret;
@@ -1246,6 +1246,7 @@ function_trace_call(unsigned long ip, un
unsigned long flags;
long disabled;
int cpu, resched;
+ unsigned long pc;
if (unlikely(!ftrace_function_enabled))
return;
@@ -1253,6 +1254,7 @@ function_trace_call(unsigned long ip, un
if (skip_trace(ip))
return;
+ pc = preempt_count();
resched = ftrace_preempt_disable();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
@@ -1260,7 +1262,7 @@ function_trace_call(unsigned long ip, un
if (likely(disabled == 1)) {
local_save_flags(flags);
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
}
atomic_dec(&data->disabled);
@@ -3531,7 +3533,7 @@ int __ftrace_printk(unsigned long ip, co
__raw_spin_lock(&data->lock);
entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
+ tracing_generic_entry_update(entry, flags, preempt_count());
entry->type = TRACE_PRINT;
entry->field.print.ip = ip;
Index: linux-2.6.26/kernel/trace/trace.h
===================================================================
--- linux-2.6.26.orig/kernel/trace/trace.h
+++ linux-2.6.26/kernel/trace/trace.h
@@ -322,7 +322,8 @@ void trace_function(struct trace_array *
struct trace_array_cpu *data,
unsigned long ip,
unsigned long parent_ip,
- unsigned long flags);
+ unsigned long flags,
+ unsigned long pc);
void tracing_event_irq(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long flags,
Index: linux-2.6.26/kernel/trace/trace_hist.c
===================================================================
--- linux-2.6.26.orig/kernel/trace/trace_hist.c
+++ linux-2.6.26/kernel/trace/trace_hist.c
@@ -354,7 +354,7 @@ notrace void tracing_hist_preempt_stop(i
cpu = raw_smp_processor_id();
#ifdef CONFIG_INTERRUPT_OFF_HIST
- if (irqs_on &&
+ if (irqs_on &&
per_cpu(hist_irqsoff_tracing, cpu)) {
stop = ftrace_now(cpu);
stop_set++;
Index: linux-2.6.26/kernel/trace/trace_irqsoff.c
===================================================================
--- linux-2.6.26.orig/kernel/trace/trace_irqsoff.c
+++ linux-2.6.26/kernel/trace/trace_irqsoff.c
@@ -99,7 +99,8 @@ irqsoff_tracer_call(unsigned long ip, un
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags,
+ preempt_count());
atomic_dec(&data->disabled);
}
@@ -154,7 +155,8 @@ check_critical_timing(struct trace_array
if (!report_latency(delta))
goto out_unlock;
- trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+ trace_function(tr, data, CALLER_ADDR0, parent_ip, flags,
+ preempt_count());
latency = nsecs_to_usecs(delta);
@@ -178,7 +180,8 @@ out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
tracing_reset(data);
- trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+ trace_function(tr, data, CALLER_ADDR0, parent_ip, flags,
+ preempt_count());
}
static inline void
@@ -211,7 +214,7 @@ start_critical_timing(unsigned long ip,
local_save_flags(flags);
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, preempt_count());
per_cpu(tracing_cpu, cpu) = 1;
@@ -245,7 +248,7 @@ stop_critical_timing(unsigned long ip, u
atomic_inc(&data->disabled);
local_save_flags(flags);
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, preempt_count());
check_critical_timing(tr, data, parent_ip ? : ip, cpu);
data->critical_start = 0;
atomic_dec(&data->disabled);
Index: linux-2.6.26/kernel/trace/trace_sched_wakeup.c
===================================================================
--- linux-2.6.26.orig/kernel/trace/trace_sched_wakeup.c
+++ linux-2.6.26/kernel/trace/trace_sched_wakeup.c
@@ -44,10 +44,12 @@ wakeup_tracer_call(unsigned long ip, uns
long disabled;
int resched;
int cpu;
+ unsigned long pc;
if (likely(!wakeup_task) || !ftrace_enabled)
return;
+ pc = preempt_count();
resched = ftrace_preempt_disable();
cpu = raw_smp_processor_id();
@@ -71,7 +73,7 @@ wakeup_tracer_call(unsigned long ip, uns
/* interrupts are disabled, no worry about scheduling */
preempt_enable_no_resched_notrace();
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
preempt_disable_notrace();
unlock:
@@ -149,7 +151,8 @@ probe_wakeup_sched_switch(struct rq *rq,
if (unlikely(!tracer_enabled || next != wakeup_task))
goto out_unlock;
- trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags);
+ trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags,
+ preempt_count());
/*
* usecs conversion is slow so we try to delay the conversion
@@ -250,7 +253,7 @@ probe_wakeup(struct rq *rq, struct task_
wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu],
- CALLER_ADDR1, CALLER_ADDR2, flags);
+ CALLER_ADDR1, CALLER_ADDR2, flags, preempt_count());
out_locked:
__raw_spin_unlock(&wakeup_lock);
--
next prev parent reply other threads:[~2009-01-28 21:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-28 21:28 [patch-rt 0/4] Bugfixes for 2.6.26-rt Thomas Gleixner
2009-01-28 21:29 ` [patch-rt 1/4] ftrace: fix swapped nibbles in tracer raw hex output Thomas Gleixner
2009-01-28 21:29 ` [patch-rt 2/4] ftrace: fix erroneous histogram stop WARN_ON() messages Thomas Gleixner
2009-01-28 21:29 ` Thomas Gleixner [this message]
2009-01-28 21:29 ` [patch-rt 4/4] sched: mark SCHED_HRTICK broken Thomas Gleixner
2009-01-29 9:58 ` Peter Zijlstra
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