From: Tim Blechmann <tim@klingt.org>
To: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org
Subject: [PATCH] Revert "sched, x86: Optimize branch hint in __switch_to()"
Date: Wed, 02 Dec 2009 12:32:10 +0100 [thread overview]
Message-ID: <4B16503A.8030508@klingt.org> (raw)
In-Reply-To: <tip-a3a1de0c34de6f5f8332cd6151c46af7813c0fcb@git.kernel.org>
[-- Attachment #1: Type: text/plain, Size: 393 bytes --]
This reverts commit a3a1de0c34de6f5f8332cd6151c46af7813c0fcb.
Commit 8ec6993d9f7d961014af970ded57542961fe9ad9 cleared the es and ds
selectors, so the original branch hints are correct now. Therefore
the branch hint doesn't need to be removed.
Signed-off-by: Tim Blechmann <tim@klingt.org>
---
arch/x86/kernel/process_64.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
[-- Attachment #2: 0001-Revert-sched-x86-Optimize-branch-hint-in-__switch_to.patch --]
[-- Type: text/x-patch, Size: 595 bytes --]
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 93c501d..eb62cbc 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -406,10 +406,11 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
* This won't pick up thread selector changes, but I guess that is ok.
*/
savesegment(es, prev->es);
- if (next->es | prev->es)
+ if (unlikely(next->es | prev->es))
loadsegment(es, next->es);
+
savesegment(ds, prev->ds);
- if (next->ds | prev->ds)
+ if (unlikely(next->ds | prev->ds))
loadsegment(ds, next->ds);
next prev parent reply other threads:[~2009-12-02 11:32 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 ` Tim Blechmann [this message]
2009-12-02 13:27 ` [tip:sched/core] Revert "sched, x86: Optimize branch hint in __switch_to()" tip-bot for Tim Blechmann
2009-11-24 10:55 ` [PATCH 2/5] sched.c: change branch hint Tim Blechmann
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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