From 44d892787efab3795cf8c708b0cb5534cd90cdeb Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Mon, 16 Feb 2015 16:42:59 +0530 Subject: 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 [rameezmustafa@codeaurora.org: Port to msm-3.18] Signed-off-by: Syed Rameez Mustafa --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index 0a8ff7c97d54..82d7dd8300a4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -174,7 +174,7 @@ extern unsigned long nr_iowait(void); extern unsigned long nr_iowait_cpu(int cpu); extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load); -extern void sched_update_nr_prod(int cpu, unsigned long nr, bool inc); +extern void sched_update_nr_prod(int cpu, long delta, bool inc); extern void sched_get_nr_running_avg(int *avg, int *iowait_avg); extern void calc_global_load(unsigned long ticks); -- cgit v1.2.3