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From: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>, Gautham R Shenoy <ego@in.ibm.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: [BUG] idle_balance() does not call load_balance_newidle()
Date: Mon, 8 Dec 2008 20:52:49 +0530	[thread overview]
Message-ID: <20081208152249.GI5457@dirshya.in.ibm.com> (raw)

Hi,

load_balance_newidle() does not get called if SD_BALANCE_NEWIDLE is
set at higher level domain (3-CPU) and not in low level domain (2-MC).

pulled_task is initialised to -1 and checked for non-zero which is
always true if the lowest level sched_domain does not have
SD_BALANCE_NEWIDLE flag set.

Trivial fix to initialise pulled_task to zero.
Patch against 2.6.28-rc7

Thanks,
Vaidy

Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
---

 kernel/sched.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/kernel/sched.c b/kernel/sched.c
index f79c7c4..4abdce1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3801,7 +3801,7 @@ out_balanced:
 static void idle_balance(int this_cpu, struct rq *this_rq)
 {
 	struct sched_domain *sd;
-	int pulled_task = -1;
+	int pulled_task = 0;
 	unsigned long next_balance = jiffies + HZ;
 	cpumask_t tmpmask;
 

             reply	other threads:[~2008-12-08 15:19 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-08 15:22 Vaidyanathan Srinivasan [this message]
2008-12-08 15:27 ` [BUG] idle_balance() does not call load_balance_newidle() Peter Zijlstra
2008-12-08 15:49 ` Ingo Molnar
2008-12-09  4:07   ` Vaidyanathan Srinivasan
2008-12-09  6:34     ` Ingo Molnar
2008-12-09  8:22       ` Vaidyanathan Srinivasan

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