Commit Graph

3 Commits

Author SHA1 Message Date
Srivatsa Vaddagiri 8f9ba192b6 sched: Keep track of average nr_big_tasks
Extend sched_get_nr_running_avg() API to return average nr_big_tasks,
in addition to average nr_running and average nr_io_wait tasks. Also
add a new trace point to record values returned by
sched_get_nr_running_avg() API.

Change-Id: Id3591e6d04da8db484b4d1cb9d95dba075f5ab9a
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
2015-02-26 10:37:26 -08:00
Srivatsa Vaddagiri 3f116af70d sched: Fix bug in average nr_running and nr_iowait calculation
sched_get_nr_running_avg() returns average nr_running and nr_iowait
task count since it was last invoked. Fix several bugs in their
calculation.

* sched_update_nr_prod() needs to consider that nr_running count can
  change by more than 1 when CFS_BANDWIDTH feature is used

* sched_get_nr_running_avg() needs to sum up nr_iowait count across
  all cpus, rather than just one

* sched_get_nr_running_avg() could race with sched_update_nr_prod(),
  as a result of which it could use curr_time which is behind a cpu's
  'last_time' value. That would lead to erroneous calculation of
  average nr_running or nr_iowait.

While at it, fix also a bug in BUG_ON() check in
sched_update_nr_prod() function and remove unnecessary nr_running
argument to sched_update_nr_prod() function.

Change-Id: I46737614737292fae0d7204c4648fb9b862f65b2
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
2015-02-26 10:33:52 -08:00
Jeff Ohlstein e14d767ab7 sched_avg: add run queue averaging
Add code to calculate the run queue depth of a cpu and iowait
depth of the cpu.

The scheduler calls in to sched_update_nr_prod whenever there
is a runqueue change. This function maintains the runqueue average
and the iowait of that cpu in that time interval.

Whoever wants to know the runqueue average is expected to call
sched_get_nr_running_avg periodically to get the accumulated
runqueue and iowait averages for all the cpus.

Change-Id: Id8cb2ecf0ed479f090a83ccb72dd59c53fa73e0c
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
(cherry picked from commit 0299fcaaad80e2c0ac9aa583c95107f6edc27750)
2013-07-08 05:51:38 -07:00