From 799fd44cf5bbcc51c46b674035bfc49cbf6907ba Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> Date: Mon, 2 Nov 2015 13:08:26 -0500 Subject: tracing: Call on_each_cpu() when adding or removing single pids from set_event_pid For the case where pids are already in set_event_pid, and one is added or removed then each CPU should be checked to make sure that the new or old pid is on or not on a CPU. For example: # echo 123 >> set_event_pid or # echo '!123' >> set_event_pid Link: http://lkml.kernel.org/r/20151030061643.GA19480@cac Suggested-by: Jiaxing Wang <hello.wjx@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/trace/trace_events.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index fb0261e90acc..292bccf3e011 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1729,14 +1729,15 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, tr, INT_MAX); register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr, 0); - - /* - * Ignoring of pids is done at task switch. But we have to - * check for those tasks that are currently running. - */ - on_each_cpu(ignore_task_cpu, tr, 1); } + /* + * Ignoring of pids is done at task switch. But we have to + * check for those tasks that are currently running. + * Always do this in case a pid was appended or removed. + */ + on_each_cpu(ignore_task_cpu, tr, 1); + mutex_unlock(&event_mutex); ret = read; -- cgit v1.2.3