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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-08 19:24:28 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-08 19:24:28 +0100 |
| commit | a622cf69b806bbb1887913c04e01d0c25b892876 (patch) | |
| tree | 08c2da8eea9ab32957735672514c603e96a402be | |
| parent | Merge branch 'oprofile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux... (diff) | |
| parent | sched: optimize sched_clock() a bit (diff) | |
| download | linux-a622cf69b806bbb1887913c04e01d0c25b892876.tar.xz linux-a622cf69b806bbb1887913c04e01d0c25b892876.zip | |
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: optimize sched_clock() a bit
sched: improve sched_clock() performance
| -rw-r--r-- | arch/x86/include/asm/msr.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/tsc.h | 8 | ||||
| -rw-r--r-- | 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 46be2fa7ac26..c2a812ebde89 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 38ae163cc91b..9cd83a8e40d5 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 2ef80e301925..424093b157d3 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 |