From: Steven Rostedt Date: Tue, 17 Mar 2009 01:57:17 +0000 (-0400) Subject: tracing: stop comm recording on tracing off X-Git-Tag: firefly_0821_release~13991^2~226^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6adaad14d7d4d3ef31b4e2dc992b18b5da7c4eb3;p=firefly-linux-kernel-4.4.55.git tracing: stop comm recording on tracing off Impact: fix for losing comms in trace The command lines of tasks are cached at sched switch to not need to record them at every trace point. Disabling the tracing on stops the recording of traces, but does not stop the caching of command lines. When the tracing is off the cache may overflow and cause the tracing to show incorrect tasks matching the PIDs. This patch disables prevents updates to the comm cache when the ring buffer is off. Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2796bd2b17e4..8f89690230e6 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -797,7 +797,7 @@ void trace_find_cmdline(int pid, char comm[]) void tracing_record_cmdline(struct task_struct *tsk) { - if (atomic_read(&trace_record_cmdline_disabled)) + if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) return; trace_save_cmdline(tsk);