From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
Morten Rasmussen <morten.rasmussen@arm.com>
Subject: [PATCH 2/7] sched/fair: Fix comment in calculate_imbalance()
Date: Fri, 29 Apr 2016 20:32:39 +0100 [thread overview]
Message-ID: <1461958364-675-3-git-send-email-dietmar.eggemann@arm.com> (raw)
In-Reply-To: <1461958364-675-1-git-send-email-dietmar.eggemann@arm.com>
The comment survived from commit 2dd73a4f09be ("[PATCH] sched:
implement smpnice") in which the selection of busiest and
busiest->avg_load (max_load) was based on if(avg_load > max_load
&& sum_nr_running > group->cpu_power / SCHED_LOAD_SCALE).
Commit b18855500fc4 ("sched/balancing: Fix 'local->avg_load >
sds->avg_load' case in calculate_imbalance()") added the second
operand of the or operator.
Update this comment accordingly and also use the current variable
names.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
kernel/sched/fair.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c77e01b55ec2..bc19fee94f39 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6998,9 +6998,10 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
}
/*
- * In the presence of smp nice balancing, certain scenarios can have
- * max load less than avg load(as we skip the groups at or below
- * its cpu_capacity, while calculating max_load..)
+ * Avg load of busiest sg can be less and avg load of local sg can
+ * be greater than avg load across all sgs of sd because avg load
+ * factors in sg capacity and sgs with smaller group_type are
+ * skipped when updating the busiest sg.
*/
if (busiest->avg_load <= sds->avg_load ||
local->avg_load >= sds->avg_load) {
--
1.9.1
next prev parent reply other threads:[~2016-04-29 19:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-29 19:32 [PATCH 0/7] sched/fair: fixes and cleanups Dietmar Eggemann
2016-04-29 19:32 ` [PATCH 1/7] sched/fair: Remove remaining power aware scheduling comments Dietmar Eggemann
2016-05-05 9:42 ` [tip:sched/core] sched/fair: Remove stale " tip-bot for Dietmar Eggemann
2016-04-29 19:32 ` Dietmar Eggemann [this message]
2016-05-05 9:42 ` [tip:sched/core] sched/fair: Fix comment in calculate_imbalance() tip-bot for Dietmar Eggemann
2016-04-29 19:32 ` [PATCH 3/7] sched/fair: Correct unit of load_above_capacity Dietmar Eggemann
2016-05-03 10:52 ` Peter Zijlstra
2016-05-03 14:56 ` Morten Rasmussen
2016-05-12 10:31 ` [tip:sched/core] " tip-bot for Morten Rasmussen
2016-05-12 21:48 ` Yuyang Du
2016-05-13 8:22 ` Vincent Guittot
2016-05-19 15:36 ` Morten Rasmussen
2016-05-20 8:17 ` Vincent Guittot
2016-05-23 20:24 ` Yuyang Du
2016-05-30 22:35 ` Yuyang Du
2016-04-29 19:32 ` [PATCH 4/7] sched/fair: Clean up the logic in fix_small_imbalance() Dietmar Eggemann
2016-05-03 10:12 ` Peter Zijlstra
2016-05-03 16:53 ` Dietmar Eggemann
2016-04-29 19:32 ` [PATCH 5/7] sched/fair: Remove cpu_avg_load_per_task() Dietmar Eggemann
2016-04-29 19:32 ` [PATCH 6/7] sched/fair: Reorder code in update_sd_lb_stats() Dietmar Eggemann
2016-04-29 19:32 ` [PATCH 7/7] sched/fair: Use group_cfs_rq(se) instead of se->my_q Dietmar Eggemann
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