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From: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Mike Galbraith <efault@gmx.de>
Subject: [git pull] scheduler updates
Date: Sat, 8 Nov 2008 18:02:24 +0100	[thread overview]
Message-ID: <20081108170224.GA553@elte.hu> (raw)

Linus,

Please pull the latest scheduler updates git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git sched-fixes-for-linus

 Thanks,

	Ingo

------------------>
Ingo Molnar (2):
      sched: improve sched_clock() performance
      sched: optimize sched_clock() a bit


 arch/x86/include/asm/msr.h |    2 --
 arch/x86/include/asm/tsc.h |    8 +++++++-
 arch/x86/kernel/tsc.c      |    2 +-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 46be2fa..c2a812e 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -108,9 +108,7 @@ static __always_inline unsigned long long __native_read_tsc(void)
 {
 	DECLARE_ARGS(val, low, high);
 
-	rdtsc_barrier();
 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
-	rdtsc_barrier();
 
 	return EAX_EDX_VAL(val, low, high);
 }
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index 38ae163..9cd83a8 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -34,6 +34,8 @@ static inline cycles_t get_cycles(void)
 
 static __always_inline cycles_t vget_cycles(void)
 {
+	cycles_t cycles;
+
 	/*
 	 * We only do VDSOs on TSC capable CPUs, so this shouldnt
 	 * access boot_cpu_data (which is not VDSO-safe):
@@ -42,7 +44,11 @@ static __always_inline cycles_t vget_cycles(void)
 	if (!cpu_has_tsc)
 		return 0;
 #endif
-	return (cycles_t)__native_read_tsc();
+	rdtsc_barrier();
+	cycles = (cycles_t)__native_read_tsc();
+	rdtsc_barrier();
+
+	return cycles;
 }
 
 extern void tsc_init(void);
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2ef80e3..424093b 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -55,7 +55,7 @@ u64 native_sched_clock(void)
 	rdtscll(this_offset);
 
 	/* return the value in ns */
-	return cycles_2_ns(this_offset);
+	return __cycles_2_ns(this_offset);
 }
 
 /* We need to define a real function for sched_clock, to override the

             reply	other threads:[~2008-11-08 17:02 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-08 17:02 Ingo Molnar [this message]
2008-11-08 18:28 ` [git pull] scheduler updates Linus Torvalds
2008-11-08 18:38   ` Linus Torvalds
2008-11-08 18:41   ` Arjan van de Ven
2008-11-08 19:00     ` Linus Torvalds
2008-11-08 19:05       ` Ingo Molnar
2008-11-08 19:20         ` Linus Torvalds
2008-11-08 19:29           ` Ingo Molnar
2008-11-17 22:43             ` Venki Pallipadi
2008-11-17 22:50               ` Ingo Molnar
2008-11-17 23:04                 ` Venki Pallipadi
2008-11-17 23:13                   ` Ingo Molnar
2008-11-08 19:40           ` Ingo Molnar
2008-11-08 19:10       ` Ingo Molnar
2008-11-08 18:52   ` Ingo Molnar
2008-11-08 18:57     ` Ingo Molnar
2008-11-08 19:32     ` Ingo Molnar
  -- strict thread matches above, loose matches on Subject: below --
2018-02-06 21:38 [GIT PULL] " Ingo Molnar
2008-03-21 16:23 [git pull] " Ingo Molnar
2008-02-29 18:04 Ingo Molnar
2008-02-13 15:58 Ingo Molnar
2008-01-31 21:54 Ingo Molnar
2007-12-30 16:45 Ingo Molnar
2007-10-24 16:39 Ingo Molnar

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