[PATCH AUTOSEL 5.6 37/68] sched/fair: Fix condition of avg_load calculation

Sasha Levin
2020-04-10T03:47:24Z

From: Tao Zhou <ouwen210@hotmail.com>

[ Upstream commit 6c8116c914b65be5e4d6f66d69c8142eb0648c22 ]

In update_sg_wakeup_stats(), the comment says:

Computing avg_load makes sense only when group is fully
busy or overloaded.

But, the code below this comment does not check like this.

From reading the code about avg_load in other functions, I
confirm that avg_load should be calculated in fully busy or
overloaded case. The comment is correct and the checking
condition is wrong. So, change that condition.

Fixes: 57abff067a08 ("sched/fair: Rework find_idlest_group()")
Signed-off-by: Tao Zhou <ouwen210@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/Message-ID:
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/sched/fair.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c1217bfe5e819..7f895d5139948 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8345,7 +8345,8 @@ static inline void update_sg_wakeup_stats(struct sched_domain *sd,
* Computing avg_load makes sense only when group is fully busy or
* overloaded
*/
- if (sgs->group_type < group_fully_busy)
+ if (sgs->group_type == group_fully_busy ||
+ sgs->group_type == group_overloaded)
sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
sgs->group_capacity;
}
--
2.20.1