Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

[linux-2.6-microblaze.git] / Documentation / trace / hwlat_detector.rst

diff --git a/Documentation/trace/hwlat_detector.rst b/Documentation/trace/hwlat_detector.rst
index 5739349..de94b49 100644 (file)
--- a/Documentation/trace/hwlat_detector.rst
+++ b/Documentation/trace/hwlat_detector.rst
@@ -76,8 +76,13 @@ in /sys/kernel/tracing:
  - tracing_cpumask     - the CPUs to move the hwlat thread across
  - hwlat_detector/width        - specified amount of time to spin within window (usecs)
  - hwlat_detector/window       - amount of time between (width) runs (usecs)
+ - hwlat_detector/mode - the thread mode
 
-The hwlat detector's kernel thread will migrate across each CPU specified in
-tracing_cpumask between each window. To limit the migration, either modify
-tracing_cpumask, or modify the hwlat kernel thread (named [hwlatd]) CPU
-affinity directly, and the migration will stop.
+By default, one hwlat detector's kernel thread will migrate across each CPU
+specified in cpumask at the beginning of a new window, in a round-robin
+fashion. This behavior can be changed by changing the thread mode,
+the available options are:
+
+ - none:        do not force migration
+ - round-robin: migrate across each CPU specified in cpumask [default]
+ - per-cpu:     create one thread for each cpu in tracing_cpumask