From aa4a221875873d2a1f9656cb7fd7e545e952b4fa Mon Sep 17 00:00:00 2001 From: Vince Weaver Date: Fri, 3 Jun 2011 17:54:40 -0400 Subject: [PATCH] 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 Cc: David Ahern Cc: Peter Zijlstra Cc: paulus@samba.org Cc: acme@redhat.com Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106031751170.29381@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 6 ++++++ 1 file changed, 6 insertions(+) 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,