diff options
| author | Andi Kleen <ak@suse.de> | 2006-01-11 16:45:24 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 22:04:58 -0500 |
| commit | c818a18146997d1356a4840b0c01f1168c16c8a4 (patch) | |
| tree | 8d7e049742e87666bf3089fe46e04828b6417fd7 /arch/x86_64/kernel/vsyscall.c | |
| parent | 7f6c5b046978d68e69bdc73433ead41612a2a1c9 (diff) | |
[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) | |||
| 66 | (__jiffies - __wall_jiffies) * (1000000 / HZ); | 66 | (__jiffies - __wall_jiffies) * (1000000 / HZ); |
| 67 | 67 | ||
| 68 | if (__vxtime.mode != VXTIME_HPET) { | 68 | if (__vxtime.mode != VXTIME_HPET) { |
| 69 | sync_core(); | 69 | t = get_cycles_sync(); |
| 70 | rdtscll(t); | ||
| 71 | if (t < __vxtime.last_tsc) | 70 | if (t < __vxtime.last_tsc) |
| 72 | t = __vxtime.last_tsc; | 71 | t = __vxtime.last_tsc; |
| 73 | usec += ((t - __vxtime.last_tsc) * | 72 | usec += ((t - __vxtime.last_tsc) * |