The body of description is mostly copied from comments in kernel/latencytop.c
Cc: Arjan van de Ven <ar...@linux.intel.com> Cc: Jonathan Corbet <cor...@lwn.net> Signed-off-by: Feng Tang <feng.t...@intel.com> --- Documentation/sysctl/kernel.txt | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index c0527d8..080ef66 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -43,6 +43,7 @@ show up in /proc/sys/kernel: - hyperv_record_panic_msg - kexec_load_disabled - kptr_restrict +- latencytop - l2cr [ PPC only ] - modprobe ==> Documentation/debugging-modules.txt - modules_disabled @@ -437,6 +438,23 @@ When kptr_restrict is set to (2), kernel pointers printed using ============================================================== +latencytop: + +This value controls whether to start collecting kernel latency +data, it is off (0) by default, and could be switched on (1). +The latency talked here is not the 'traditional' interrupt +latency (which is primarily caused by something else consuming CPU), +but instead, it is the latency an application encounters because +the kernel sleeps on its behalf for various reasons. + +The info is exported via /proc/latency_stats and /proc/<pid>/latency. + +This file shows up only if CONFIG_LATENCYTOP is enabled, and please +be noted that turning it on may bring notable sytstem overhead when +there are massive scheduling in system. + +============================================================== + l2cr: (PPC only) This flag controls the L2 cache of G3 processor boards. If -- 2.7.4
