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[PATCH] x86_64: fix sync before RDTSC on Intel cpus
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Commit c818a18 didn't do the expected
thing.  This fix will remove the additional sync(cpuid) before RDTSC on
Intel platforms..

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Siddha, Suresh B authored and Linus Torvalds committed Apr 11, 2006
1 parent 97a4d00 commit e4cff6a
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion include/asm-x86_64/timex.h
Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@ static __always_inline cycles_t get_cycles_sync(void)
unsigned eax;
/* Don't do an additional sync on CPUs where we know
RDTSC is already synchronous. */
alternative_io(ASM_NOP2, "cpuid", X86_FEATURE_SYNC_RDTSC,
alternative_io("cpuid", ASM_NOP2, X86_FEATURE_SYNC_RDTSC,
"=a" (eax), "0" (1) : "ebx","ecx","edx","memory");
rdtscll(ret);
return ret;
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