diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2008-10-04 10:01:00 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-14 12:39:20 +0400 |
| commit | 3ea2e6d71aafe35b8aaf89ed711a283815acfae6 (patch) | |
| tree | e4bae61f9bbe5ff7ccf6eac95416b98ebd4974a4 /kernel/trace/trace_sched_switch.c | |
| parent | bf41a158cacba6ca5fc6407a54e7ad8ce1567e2e (diff) | |
| download | linux-3ea2e6d71aafe35b8aaf89ed711a283815acfae6.tar.xz | |
ftrace: make some tracers reentrant
Now that the ring buffer is reentrant, some of the ftrace tracers
(sched_swich, debugging traces) can also be reentrant.
Note: Never make the function tracer reentrant, that can cause
recursion problems all over the kernel. The function tracer
must disable reentrancy.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace_sched_switch.c')
| -rw-r--r-- | kernel/trace/trace_sched_switch.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index c7fa08a5b7f4..b8f56beb1a62 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -24,7 +24,6 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, { struct trace_array_cpu *data; unsigned long flags; - long disabled; int cpu; int pc; @@ -41,12 +40,10 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, local_irq_save(flags); cpu = raw_smp_processor_id(); data = ctx_trace->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) + if (likely(!atomic_read(&data->disabled))) tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } @@ -55,7 +52,6 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) { struct trace_array_cpu *data; unsigned long flags; - long disabled; int cpu, pc; if (!likely(tracer_enabled)) @@ -67,13 +63,11 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) local_irq_save(flags); cpu = raw_smp_processor_id(); data = ctx_trace->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) + if (likely(!atomic_read(&data->disabled))) tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } |