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| author | Otavio Salvador <otavio@ossystems.com.br> | 2017-12-13 18:16:19 -0200 |
|---|---|---|
| committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2017-12-21 15:01:33 +0100 |
| commit | fb2d2dee504a963efdcb76517b5cdf25444cf535 (patch) | |
| tree | f1b58594ba11c6c41c3acddde35890f68c42ea9e /samples/trace_events/trace-events-sample.c | |
| parent | effee16e4c0cc8b570d372e33633e9f9bc8359c7 (diff) | |
| parent | d9f7e5584f0e3e34a2c14825657a6b31e7184171 (diff) | |
Merge pull request #21 from falstaff84/4.9-1.0.x-imx-fixes-stable-merge
4.9-1.0.x-imx stable 4.9.67 merge
Diffstat (limited to 'samples/trace_events/trace-events-sample.c')
| -rw-r--r-- | samples/trace_events/trace-events-sample.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c index 880a7d1d27d2..4ccff66523c9 100644 --- a/samples/trace_events/trace-events-sample.c +++ b/samples/trace_events/trace-events-sample.c @@ -78,28 +78,36 @@ static int simple_thread_fn(void *arg) } static DEFINE_MUTEX(thread_mutex); +static int simple_thread_cnt; void foo_bar_reg(void) { + mutex_lock(&thread_mutex); + if (simple_thread_cnt++) + goto out; + pr_info("Starting thread for foo_bar_fn\n"); /* * We shouldn't be able to start a trace when the module is * unloading (there's other locks to prevent that). But * for consistency sake, we still take the thread_mutex. */ - mutex_lock(&thread_mutex); simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); + out: mutex_unlock(&thread_mutex); } void foo_bar_unreg(void) { - pr_info("Killing thread for foo_bar_fn\n"); - /* protect against module unloading */ mutex_lock(&thread_mutex); + if (--simple_thread_cnt) + goto out; + + pr_info("Killing thread for foo_bar_fn\n"); if (simple_tsk_fn) kthread_stop(simple_tsk_fn); simple_tsk_fn = NULL; + out: mutex_unlock(&thread_mutex); } |