Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

[cascardo/linux.git] / Documentation / sysctl / kernel.txt

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index c831001..6fccb69 100644 (file)
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -197,8 +197,8 @@ core_pattern is used to specify a core dumpfile pattern name.
        %P      global pid (init PID namespace)
        %i      tid
        %I      global tid (init PID namespace)
-       %u      uid
-       %g      gid
+       %u      uid (in initial user namespace)
+       %g      gid (in initial user namespace)
        %d      dump mode, matches PR_SET_DUMPABLE and
                /proc/sys/fs/suid_dumpable
        %s      signal number
@@ -923,6 +923,27 @@ and nmi_watchdog.
 
 ==============================================================
 
+watchdog_cpumask:
+
+This value can be used to control on which cpus the watchdog may run.
+The default cpumask is all possible cores, but if NO_HZ_FULL is
+enabled in the kernel config, and cores are specified with the
+nohz_full= boot argument, those cores are excluded by default.
+Offline cores can be included in this mask, and if the core is later
+brought online, the watchdog will be started based on the mask value.
+
+Typically this value would only be touched in the nohz_full case
+to re-enable cores that by default were not running the watchdog,
+if a kernel lockup was suspected on those cores.
+
+The argument value is the standard cpulist format for cpumasks,
+so for example to enable the watchdog on cores 0, 2, 3, and 4 you
+might say:
+
+  echo 0,2-4 > /proc/sys/kernel/watchdog_cpumask
+
+==============================================================
+
 watchdog_thresh:
 
 This value can be used to control the frequency of hrtimer and NMI