The patch titled
sched: improve stability of smpnice load balancing
has been removed from the -mm tree. Its filename is
sched-improve-stability-of-smpnice-load-balancing.patch
This patch was dropped because it was folded into sched-implement-smpnice.patch
------------------------------------------------------
Subject: sched: improve stability of smpnice load balancing
From: Peter Williams <pwil3058@xxxxxxxxxxxxxx>
Problem:
Due to an injudicious piece of code near the end of find_busiest_group()
smpnice load balancing is too aggressive resulting in excessive movement
of tasks from one CPU to another.
Solution:
Remove the offending code. The thinking that caused it to be included
became invalid when find_busiest_queue() was modified to use average
load per task (on the relevant run queue) instead of SCHED_LOAD_SCALE
when evaluating small imbalance values to see whether they warranted
being moved.
Signed-off-by: Peter Williams <pwil3058@xxxxxxxxxxxxxx>
Cc: "Siddha, Suresh B" <suresh.b.siddha@xxxxxxxxx>
Cc: Con Kolivas <kernel@xxxxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Cc: "Chen, Kenneth W" <kenneth.w.chen@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/sched.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff -puN kernel/sched.c~sched-improve-stability-of-smpnice-load-balancing kernel/sched.c
--- devel/kernel/sched.c~sched-improve-stability-of-smpnice-load-balancing 2006-06-09 15:18:10.000000000 -0700
+++ devel-akpm/kernel/sched.c 2006-06-09 15:18:10.000000000 -0700
@@ -2235,13 +2235,10 @@ find_busiest_group(struct sched_domain *
pwr_move /= SCHED_LOAD_SCALE;
/* Move if we gain throughput */
- if (pwr_move > pwr_now)
- *imbalance = busiest_load_per_task;
- /* or if there's a reasonable chance that *imbalance is big
- * enough to cause a move
- */
- else if (*imbalance <= busiest_load_per_task / 2)
+ if (pwr_move <= pwr_now)
goto out_balanced;
+
+ *imbalance = busiest_load_per_task;
}
return busiest;
_
Patches currently in -mm which might be from pwil3058@xxxxxxxxxxxxxx are
origin.patch
sched-implement-smpnice.patch
sched-improve-stability-of-smpnice-load-balancing.patch
sched-improve-smpnice-load-balancing-when-load-per-task.patch
sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch
sched-uninline-task_rq_lock.patch
sched-add-above-background-load-function.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-tester-fix.patch
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