diff options
| author |   Andi Kleen <ak@suse.de> | 2006-01-11 22:45:24 +0100 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 19:04:58 -0800 |
| commit | c818a18146997d1356a4840b0c01f1168c16c8a4 (patch) | |
| tree | 8d7e049742e87666bf3089fe46e04828b6417fd7 /arch/x86_64/kernel/vsyscall.c | |
| parent | [PATCH] x86_64: Support alternative() in vsyscalls (diff) | |
| download | linux-dev-c818a18146997d1356a4840b0c01f1168c16c8a4.tar.xz linux-dev-c818a18146997d1356a4840b0c01f1168c16c8a4.zip | |
[PATCH] x86_64: On Intel CPUs don't do an additional CPU sync before RDTSC
RDTSC serialization using cpuid is not needed for Intel platforms.
This increases gettimeofday performance.
Cc: vojtech@suse.cz
Cc: rohit.seth@intel.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/vsyscall.c')
| -rw-r--r-- | arch/x86_64/kernel/vsyscall.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c index 70a0bd16085f..9e51047fc410 100644 --- a/arch/x86_64/kernel/vsyscall.c +++ b/arch/x86_64/kernel/vsyscall.c @@ -66,8 +66,7 @@ static force_inline void do_vgettimeofday(struct timeval * tv) (__jiffies - __wall_jiffies) * (1000000 / HZ); if (__vxtime.mode != VXTIME_HPET) { - sync_core(); - rdtscll(t); + t = get_cycles_sync(); if (t < __vxtime.last_tsc) t = __vxtime.last_tsc; usec += ((t - __vxtime.last_tsc) * |