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| author | Steven Rostedt <srostedt@redhat.com> | 2009-03-18 02:59:53 +0300 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-03-18 06:10:45 +0300 |
| commit | 5fec6ddcb43a91aa9a254c8ecf174c803de6f07e (patch) | |
| tree | 6c8e3c0d719022e7c82d87894c9eb28492035aa5 | |
| parent | 97e7e4f391cac2b00417b581b432533d245d4fd0 (diff) | |
| download | linux-5fec6ddcb43a91aa9a254c8ecf174c803de6f07e.tar.xz | |
tracing: make sched_switch stop/start light weight
The stopping and starting of a tracer should be light weight and
be able to be called in all contexts. The sched_switch grabbed
mutexes in the start/stop functions. This patch changes it to a
simple variable, on/off.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| -rw-r--r-- | kernel/trace/trace_sched_switch.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 77132c2cf3d9..de35f200abd3 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -18,6 +18,7 @@ static struct trace_array *ctx_trace; static int __read_mostly tracer_enabled; static int sched_ref; static DEFINE_MUTEX(sched_register_mutex); +static int sched_stopped; static void probe_sched_switch(struct rq *__rq, struct task_struct *prev, @@ -28,7 +29,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, int cpu; int pc; - if (!sched_ref) + if (!sched_ref || sched_stopped) return; tracing_record_cmdline(prev); @@ -193,6 +194,7 @@ static void stop_sched_trace(struct trace_array *tr) static int sched_switch_trace_init(struct trace_array *tr) { ctx_trace = tr; + tracing_reset_online_cpus(tr); tracing_start_sched_switch_record(); return 0; } @@ -205,13 +207,12 @@ static void sched_switch_trace_reset(struct trace_array *tr) static void sched_switch_trace_start(struct trace_array *tr) { - tracing_reset_online_cpus(tr); - tracing_start_sched_switch(); + sched_stopped = 0; } static void sched_switch_trace_stop(struct trace_array *tr) { - tracing_stop_sched_switch(); + sched_stopped = 1; } static struct tracer sched_switch_trace __read_mostly = |