Re: [patch] sched: fix the all pinned logic inload_balance_newidle()

From: Ingo Molnar
Date: Tue Jul 17 2007 - 04:22:24 EST



* Siddha, Suresh B <suresh.b.siddha@xxxxxxxxx> wrote:

> nr_moved is not the correct check for triggering all pinned logic. Fix
> the all pinned logic in the case of load_balance_newidle().

indeeed.

i've applied your patch to my queue. (I've done a trivial style change
to it, see below.)

Ingo

--------------------->
Subject: sched: fix the all pinned logic in load_balance_newidle()
From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

nr_moved is not the correct check for triggering all pinned logic. Fix
the all pinned logic in the case of load_balance_newidle().

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

Index: linux/kernel/sched.c
===================================================================
--- linux.orig/kernel/sched.c
+++ linux/kernel/sched.c
@@ -2679,6 +2679,7 @@ load_balance_newidle(int this_cpu, struc
unsigned long imbalance;
int nr_moved = 0;
int sd_idle = 0;
+ int all_pinned = 0;
cpumask_t cpus = CPU_MASK_ALL;

/*
@@ -2717,10 +2718,11 @@ redo:
double_lock_balance(this_rq, busiest);
nr_moved = move_tasks(this_rq, this_cpu, busiest,
minus_1_or_zero(busiest->nr_running),
- imbalance, sd, CPU_NEWLY_IDLE, NULL);
+ imbalance, sd, CPU_NEWLY_IDLE,
+ &all_pinned);
spin_unlock(&busiest->lock);

- if (!nr_moved) {
+ if (unlikely(all_pinned)) {
cpu_clear(cpu_of(busiest), cpus);
if (!cpus_empty(cpus))
goto redo;
-
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