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From: Tim Blechmann <tim@klingt.org>
To: linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] sched.c: change branch hint
Date: Tue, 24 Nov 2009 11:55:27 +0100	[thread overview]
Message-ID: <4B0BBB9F.6080304@klingt.org> (raw)
In-Reply-To: <cover.1259059549.git.tim@klingt.org>

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branch hint profiling of my nehalem machine, showed over 90% incorrect
branch hints:

10420275 170645395  94 context_switch                 sched.c
   3043
10408421 171098521  94 context_switch                 sched.c
   3050

Signed-off-by: Tim Blechmann <tim@klingt.org>
---
 kernel/sched.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index c78dcfe..2a78b38 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3040,14 +3040,14 @@ context_switch(struct rq *rq, struct task_struct
*prev,
 	 */
 	arch_start_context_switch(prev);
 -	if (unlikely(!mm)) {
+	if (likely(!mm)) {
 		next->active_mm = oldmm;
 		atomic_inc(&oldmm->mm_count);
 		enter_lazy_tlb(oldmm, next);
 	} else
 		switch_mm(oldmm, mm, next);
 -	if (unlikely(!prev->mm)) {
+	if (likely(!prev->mm)) {
 		prev->active_mm = NULL;
 		rq->prev_mm = oldmm;
 	}
-- 
1.6.4.2



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  parent reply	other threads:[~2009-11-24 11:12 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1259059549.git.tim@klingt.org>
2009-11-24 10:55 ` [PATCH 1/5] process_64: remove branch hint Tim Blechmann
2009-11-24 16:57   ` [tip:sched/core] sched, x86: Optimize branch hint in __switch_to() tip-bot for Tim Blechmann
2009-11-24 17:28     ` Brian Gerst
2009-11-25  9:03       ` Tim Blechmann
2009-11-25 15:53         ` Brian Gerst
2009-11-25 16:16           ` index 780cd92..22db86a 100644 Brian Gerst
2009-11-25 16:17           ` [PATCH] x86, 64-bit: Set data segments to null after switching to 64-bit mode Brian Gerst
2009-11-26  9:56             ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-11-29 11:44             ` [PATCH] " Tim Blechmann
2009-12-02 11:32     ` [PATCH] Revert "sched, x86: Optimize branch hint in __switch_to()" Tim Blechmann
2009-12-02 13:27       ` [tip:sched/core] " tip-bot for Tim Blechmann
2009-11-24 10:55 ` Tim Blechmann [this message]
2009-11-24 16:56   ` [tip:sched/core] sched: Optimize branch hint in context_switch() tip-bot for Tim Blechmann
2009-11-24 10:55 ` [PATCH 3/5] slab.c: remove branch hint Tim Blechmann
2009-11-24 11:20   ` Ingo Molnar
2009-11-24 11:28     ` Pekka Enberg
2009-11-24 11:42       ` Ingo Molnar
2009-11-25 10:41         ` Pekka Enberg
2009-11-24 11:45       ` Tim Blechmann
2009-11-29 11:36       ` Tim Blechmann
2009-11-30  9:05         ` Pekka Enberg
2009-11-30 16:09           ` Christoph Lameter
2009-11-30 17:44             ` Pekka Enberg
2009-11-30 17:50               ` Christoph Lameter
2009-11-30 17:59               ` [PATCH] branch profiling on my nehalem machine showed 99% incorrect branch hints: Tim Blechmann
2009-12-06  8:33                 ` Pekka Enberg
2009-11-24 10:55 ` [PATCH 4/5] sched_fair.c: remove branch hint Tim Blechmann
2009-11-24 16:56   ` [tip:sched/core] sched: Optimize branch hint in pick_next_task_fair() tip-bot for Tim Blechmann
2009-11-24 10:55 ` [PATCH 5/5] workqueue.c: remove branch hint Tim Blechmann

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