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

Steven Rostedt (Red Hat) committed 11 years ago

Commit 799fd441 parent fb662281 file · +7 −6Browse files

Unified · Split

kernel/trace/trace_events.c+7−6

@@ -1729,14 +1729,15 @@ ftrace_event_pid_write(struct file filp, const char __user ubuf, · 1728 unmodified lines
1729	1729	tr, INT_MAX);
1730	1730	register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1731	1731	tr, 0);
1732		−
1733		− /*
1734		− * Ignoring of pids is done at task switch. But we have to
1735		− * check for those tasks that are currently running.
1736		− */
1737		− on_each_cpu(ignore_task_cpu, tr, 1);
1738	1732	}
1739	1733
	1734	+ /*
	1735	+ * Ignoring of pids is done at task switch. But we have to
	1736	+ * check for those tasks that are currently running.
	1737	+ * Always do this in case a pid was appended or removed.
	1738	+ */
	1739	+ on_each_cpu(ignore_task_cpu, tr, 1);
	1740	+
1740	1741	mutex_unlock(&event_mutex);
1741	1742
1742	1743	ret = read;