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authorVince Weaver <vweaver1@eecs.utk.edu>2011-06-03 17:54:40 -0400
committerIngo Molnar <mingo@elte.hu>2011-06-04 12:22:04 +0200
commitaa4a221875873d2a1f9656cb7fd7e545e952b4fa (patch)
tree44f66345c06c94cfc95d17b337d45e09917e475d
parent710054ba25c0d1f8f41c22ce13ba336503fb5318 (diff)
perf: Comment /proc/sys/kernel/perf_event_paranoid to be part of user ABI
Turns out that distro packages use this file as an indicator of the perf event subsystem - this is easier to check for from scripts than the existence of the system call. This is easy enough to keep around for the kernel, so add a comment to make sure it stays so. Signed-off-by: Vince Weaver <vweaver1@eecs.utk.edu> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106031751170.29381@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sysctl.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 4fc92445a29..f175d98bd35 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -938,6 +938,12 @@ static struct ctl_table kern_table[] = {
},
#endif
#ifdef CONFIG_PERF_EVENTS
+ /*
+ * User-space scripts rely on the existence of this file
+ * as a feature check for perf_events being enabled.
+ *
+ * So it's an ABI, do not remove!
+ */
{
.procname = "perf_event_paranoid",
.data = &sysctl_perf_event_paranoid,