[RFC 4/4] perf Documentation: Document the per PMU perf_event_paranoid interface

[Tvrtko Ursulin <tursulin@ursulin.net>]

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Explain behaviour of the new control knob along side the existing perf
event documentation.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: x86@kernel.org
---
 .../testing/sysfs-bus-event_source-devices-events  | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 505f080d20a1..b3096ae9be6f 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
@@ -92,3 +92,17 @@ Description:	Perf event scaling factors
 
 		This is provided to avoid performing floating point arithmetic
 		in the kernel.
+
+What: /sys/bus/event_source/devices/<pmu>/perf_event_paranoid
+Date: 2018/06/26
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Per PMU access control file
+
+		This is the per PMU version of the perf_event_paranoid sysctl
+		which allows controlling the access control level for each
+		individual PMU.
+
+		Writes to the sysctl will propagate to all PMU providers.
+
+		For explanation of supported values please consult the sysctl
+		documentation.
-- 
2.17.1