diff options
author | Alex Shi <alex.shi@linaro.org> | 2017-11-09 12:01:32 +0800 |
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committer | Alex Shi <alex.shi@linaro.org> | 2017-11-09 12:01:32 +0800 |
commit | 7effd4c8ef8779ef8dcb90b5dc3dd38c12210c11 (patch) | |
tree | c681a7f96d19a8163118f842f8dcd0a3c4520cb3 /samples | |
parent | 2f68ef7576fc0a106d5cd77f31175fd498c9f995 (diff) | |
parent | c54d0707aa09a824413ebb4195c98bfb9b9e1fc0 (diff) |
Merge tag 'v4.4.97' into linux-linaro-lsk-v4.4
This is the 4.4.97 stable release
Diffstat (limited to 'samples')
-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); } |