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.

Vince Weaver committed 15 years ago

Commit aa4a2211 parent 710054b1 file · +6 −0Browse files

Showing the changes to kernel (1 of 1 file). Show all

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kernel/sysctl.c+6−0

@@ -938,6 +938,12 @@ static struct ctl_table kern_table[] = { · 937 unmodified lines
938	938	},
939	939	#endif
940	940	#ifdef CONFIG_PERF_EVENTS
	941	+ /*
	942	+ * User-space scripts rely on the existence of this file
	943	+ * as a feature check for perf_events being enabled.
	944	+ *
	945	+ * So it's an ABI, do not remove!
	946	+ */
941	947	{
942	948	.procname = "perf_event_paranoid",
943	949	.data = &sysctl_perf_event_paranoid,