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Date: Sun, 1 Jul 2007 10:45:01 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Willy Tarreau <w@1wt.eu>
Cc: linux-kernel@vger.kernel.org,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       Mike Galbraith <efault@gmx.de>, Arjan van de Ven <arjan@infradead.org>,
       Thomas Gleixner <tglx@linutronix.de>,
       Dmitry Adamushko <dmitry.adamushko@gmail.com>,
       Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Subject: Re: [patch] CFS scheduler, -v18
Message-ID: <20070701084501.GA10548@elte.hu>
References: <20070622220202.GA16872@elte.hu> <20070630210649.GA13186@1wt.eu> <20070701083102.GA4499@elte.hu>
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Willy,

could you check whether your current v18 CFS tree has the fix below 
included? I discovered it right after having released v18 so i updated 
the v18 files in place - but maybe you downloaded an early version? I 
thought it's relatively harmless, that it would only affect SCHED_IDLE 
tasks, but maybe it affects nice +19 tasks too on your box!

	Ingo

Index: linux/kernel/sched_fair.c
===================================================================
--- linux.orig/kernel/sched_fair.c
+++ linux/kernel/sched_fair.c
@@ -342,8 +342,9 @@ update_stats_enqueue(struct cfs_rq *cfs_
 		s64 tmp;
 
 		if (se->wait_runtime < 0) {
-			tmp = (0 - se->wait_runtime) << NICE_0_SHIFT;
-			key += (tmp * se->load.inv_weight) >> WMULT_SHIFT;
+			tmp = -se->wait_runtime;
+			key += (tmp * se->load.inv_weight) >>
+					(WMULT_SHIFT - NICE_0_SHIFT);
 		} else {
 			tmp = se->wait_runtime * se->load.weight;
 			key -= tmp >> NICE_0_SHIFT;