sched/fair: Fix comment in calculate_imbalance()

The comment in calculate_imbalance() was introduced in commit:

 2dd73a4f09be ("[PATCH] sched: implement smpnice")

which described the logic as it was then, but a later commit:

  b18855500fc4 ("sched/balancing: Fix 'local->avg_load > sds->avg_load' case in calculate_imbalance()")

.. complicated this logic some more so that the comment does not match anymore.

Update the comment to match the code.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1461958364-675-3-git-send-email-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 537d71e..51f7a4b 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7000,9 +7000,10 @@ 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) {