x86: kvmclock: drop rdtsc_barrier()
authorMarcelo Tosatti <mtosatti@redhat.com>
Sat, 25 Apr 2015 01:36:14 +0000 (22:36 -0300)
committerPaolo Bonzini <pbonzini@redhat.com>
Thu, 7 May 2015 09:29:48 +0000 (11:29 +0200)
commita3eb97bd80134ba07864ca00747466c02118aca1
tree07568d723daf0d61489c53bb037627d36f36878d
parentd90e3a35e90af7f8beceebefc90e62eae237c5ed
x86: kvmclock: drop rdtsc_barrier()

Drop unnecessary rdtsc_barrier(), as has been determined empirically,
see 057e6a8c660e95c3f4e7162e00e2fee1fc90c50d for details.

Noticed by Andy Lutomirski.

Improves clock_gettime() by approximately 15% on
Intel i7-3520M @ 2.90GHz.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/include/asm/pvclock.h