perf tools: Document the perf sysctls
perf_event_paranoid was only documented in source code and a perf error
message. Copy the documentation from the error message to
Documentation/sysctl/kernel.txt.
perf_cpu_time_max_percent was already documented but missing from the
list at the top, so add it there.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20160119213515.GG2637@decadent.org.uk
[ Remove reference to external Documentation file, provide info inline, as before ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 73c6b1e..c803e73 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -58,6 +58,8 @@
- panic_on_stackoverflow
- panic_on_unrecovered_nmi
- panic_on_warn
+- perf_cpu_time_max_percent
+- perf_event_paranoid
- pid_max
- powersave-nap [ PPC only ]
- printk
@@ -639,6 +641,17 @@
==============================================================
+perf_event_paranoid:
+
+Controls use of the performance events system by unprivileged
+users (without CAP_SYS_ADMIN). The default value is 1.
+
+ -1: Allow use of (almost) all events by all users
+>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
+>=1: Disallow CPU event access by users without CAP_SYS_ADMIN
+>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
+
+==============================================================
pid_max: