These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / Documentation / sysctl / kernel.txt

diff --git a/kernel/Documentation/sysctl/kernel.txt b/kernel/Documentation/sysctl/kernel.txt
index c831001..af70d15 100644 (file)
--- a/kernel/Documentation/sysctl/kernel.txt
+++ b/kernel/Documentation/sysctl/kernel.txt
@@ -33,6 +33,7 @@ show up in /proc/sys/kernel:
 - domainname
 - hostname
 - hotplug
+- hardlockup_all_cpu_backtrace
 - hung_task_panic
 - hung_task_check_count
 - hung_task_timeout_secs
@@ -197,8 +198,8 @@ 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
@@ -292,6 +293,17 @@ Information Service) or YP (Yellow Pages) domainname. These two
 domain names are in general different. For a detailed discussion
 see the hostname(1) man page.
 
+==============================================================
+hardlockup_all_cpu_backtrace:
+
+This value controls the hard lockup detector behavior when a hard
+lockup condition is detected as to whether or not to gather further
+debug information. If enabled, arch-specific all-CPU stack dumping
+will be initiated.
+
+0: do nothing. This is the default behavior.
+
+1: on detection capture more debug information.
 ==============================================================
 
 hotplug:
@@ -923,6 +935,27 @@ 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