[GIT PULL] x86/vdso for v2.6.31

[GIT PULL] x86/vdso for v2.6.31

[Ingo Molnar]

Linus,

Please pull the latest x86-vdso-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-vdso-for-linus

 Thanks,

	Ingo

------------------>
Petr Tesarik (1):
      x86: move rdtsc_barrier() into the TSC vread method


 arch/x86/kernel/tsc.c         |   11 ++++++++++-
 arch/x86/kernel/vsyscall_64.c |    8 --------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index d57de05..cf8611d 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -710,7 +710,16 @@ static cycle_t read_tsc(struct clocksource *cs)
 #ifdef CONFIG_X86_64
 static cycle_t __vsyscall_fn vread_tsc(void)
 {
-	cycle_t ret = (cycle_t)vget_cycles();
+	cycle_t ret;
+
+	/*
+	 * Surround the RDTSC by barriers, to make sure it's not
+	 * speculated to outside the seqlock critical section and
+	 * does not cause time warps:
+	 */
+	rdtsc_barrier();
+	ret = (cycle_t)vget_cycles();
+	rdtsc_barrier();
 
 	return ret >= __vsyscall_gtod_data.clock.cycle_last ?
 		ret : __vsyscall_gtod_data.clock.cycle_last;
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 44153af..25ee06a 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -132,15 +132,7 @@ static __always_inline void do_vgettimeofday(struct timeval * tv)
 			return;
 		}
 
-		/*
-		 * Surround the RDTSC by barriers, to make sure it's not
-		 * speculated to outside the seqlock critical section and
-		 * does not cause time warps:
-		 */
-		rdtsc_barrier();
 		now = vread();
-		rdtsc_barrier();
-
 		base = __vsyscall_gtod_data.clock.cycle_last;
 		mask = __vsyscall_gtod_data.clock.mask;
 		mult = __vsyscall_gtod_data.clock.mult;