From 92d745ec71fa18beeff5a9c8bda5f2183b910ce2 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 19 Jan 2016 21:35:15 +0000 Subject: BACKPORT: 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. Signed-off-by: Ben Hutchings Cc: Peter Zijlstra 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 Bug: 29054680 Change-Id: I13e73cfb2ad761c94762d0c8196df7725abdf5c5 --- Documentation/sysctl/kernel.txt | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) (limited to 'Documentation') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 8d90c42e5..f33820824 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -49,8 +49,9 @@ show up in /proc/sys/kernel: - overflowuid - panic - panic_on_oops -- panic_on_unrecovered_nmi - panic_on_stackoverflow +- panic_on_unrecovered_nmi +- perf_event_paranoid - pid_max - powersave-nap [ PPC only ] - printk @@ -402,19 +403,6 @@ the recommended setting is 60. ============================================================== -panic_on_unrecovered_nmi: - -The default Linux behaviour on an NMI of either memory or unknown is -to continue operation. For many environments such as scientific -computing it is preferable that the box is taken out and the error -dealt with than an uncorrected parity/ECC error get propagated. - -A small number of systems do generate NMI's for bizarre random reasons -such as power management so the default is off. That sysctl works like -the existing panic controls already in that directory. - -============================================================== - panic_on_oops: Controls the kernel's behaviour when an oops or BUG is encountered. @@ -464,6 +452,30 @@ allowed to execute. ============================================================== +panic_on_unrecovered_nmi: + +The default Linux behaviour on an NMI of either memory or unknown is +to continue operation. For many environments such as scientific +computing it is preferable that the box is taken out and the error +dealt with than an uncorrected parity/ECC error get propagated. + +A small number of systems do generate NMI's for bizarre random reasons +such as power management so the default is off. That sysctl works like +the existing panic controls already in that directory. + +============================================================== + +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: -- cgit v1.2.3