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| author | Tim Blechmann <tim@klingt.org> | 2009-11-24 11:55:15 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-24 12:20:04 +0100 |
| commit | a3a1de0c34de6f5f8332cd6151c46af7813c0fcb (patch) | |
| tree | 2eaff67aaf2e0c841b26054b48e2a632db211c40 | |
| parent | 710390d90f143a9ebb87a475215140f426792efd (diff) | |
| download | linux-a3a1de0c34de6f5f8332cd6151c46af7813c0fcb.tar.gz linux-a3a1de0c34de6f5f8332cd6151c46af7813c0fcb.tar.bz2 linux-a3a1de0c34de6f5f8332cd6151c46af7813c0fcb.zip | |
sched, x86: Optimize branch hint in __switch_to()
Branch hint profiling on my nehalem machine showed 96%
incorrect branch hints:
6548732 174664120 96 __switch_to process_64.c
406
6548745 174565593 96 __switch_to process_64.c
410
Signed-off-by: Tim Blechmann <tim@klingt.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B0BBB93.3080307@klingt.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/process_64.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index ad535b683170..d9db1049e86f 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -406,11 +406,10 @@ __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 (unlikely(next->es | prev->es)) + if (next->es | prev->es) loadsegment(es, next->es); - savesegment(ds, prev->ds); - if (unlikely(next->ds | prev->ds)) + if (next->ds | prev->ds) loadsegment(ds, next->ds); |