From 65daaca7c6dac4db0ef64f2baac0e448cf5d847f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 14 Jan 2014 07:06:29 -0500 Subject: tracing: Allow wakeup tracers to be used by instances The wakeup and wakeup_rt tracers can now be used by instances. But they may only be used by one instance at a time (including the top level directory). This allows multiple tracers to run while the wakeup tracer is running simultaneously. Signed-off-by: Steven Rostedt --- kernel/trace/trace_sched_wakeup.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 41e0b8aa78ed..1573c03640d2 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -601,6 +601,8 @@ static void stop_wakeup_tracer(struct trace_array *tr) unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); } +static bool wakeup_busy; + static int __wakeup_tracer_init(struct trace_array *tr) { save_flags = trace_flags; @@ -613,11 +615,16 @@ static int __wakeup_tracer_init(struct trace_array *tr) wakeup_trace = tr; ftrace_init_array_ops(tr, wakeup_tracer_call); start_wakeup_tracer(tr); + + wakeup_busy = true; return 0; } static int wakeup_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 0; wakeup_rt = 0; return __wakeup_tracer_init(tr); @@ -625,6 +632,9 @@ static int wakeup_tracer_init(struct trace_array *tr) static int wakeup_rt_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 0; wakeup_rt = 1; return __wakeup_tracer_init(tr); @@ -632,6 +642,9 @@ static int wakeup_rt_tracer_init(struct trace_array *tr) static int wakeup_dl_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 1; wakeup_rt = 0; return __wakeup_tracer_init(tr); @@ -649,6 +662,7 @@ static void wakeup_tracer_reset(struct trace_array *tr) set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); ftrace_reset_array_ops(tr); + wakeup_busy = false; } static void wakeup_tracer_start(struct trace_array *tr) @@ -680,6 +694,7 @@ static struct tracer wakeup_tracer __read_mostly = #endif .open = wakeup_trace_open, .close = wakeup_trace_close, + .allow_instances = true, .use_max_tr = true, }; @@ -702,6 +717,7 @@ static struct tracer wakeup_rt_tracer __read_mostly = #endif .open = wakeup_trace_open, .close = wakeup_trace_close, + .allow_instances = true, .use_max_tr = true, }; -- cgit v1.2.3