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| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-12-30 08:02:35 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-12-30 08:02:35 +1030 |
| commit | 33edcf133ba93ecba2e4b6472e97b689895d805c (patch) | |
| tree | 327d7a20acef64005e7c5ccbfa1265be28aeb6ac /arch/x86/kernel/vsyscall_64.c | |
| parent | be4d638c1597580ed2294d899d9f1a2cd10e462c (diff) | |
| parent | 3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff) | |
| download | linux-33edcf133ba93ecba2e4b6472e97b689895d805c.tar.gz linux-33edcf133ba93ecba2e4b6472e97b689895d805c.tar.bz2 linux-33edcf133ba93ecba2e4b6472e97b689895d805c.zip | |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'arch/x86/kernel/vsyscall_64.c')
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 0b8b6690a86d..44153afc9067 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -17,6 +17,9 @@ * want per guest time just set the kernel.vsyscall64 sysctl to 0. */ +/* Disable profiling for userspace code: */ +#define DISABLE_BRANCH_PROFILING + #include <linux/time.h> #include <linux/init.h> #include <linux/kernel.h> @@ -128,7 +131,16 @@ static __always_inline void do_vgettimeofday(struct timeval * tv) gettimeofday(tv,NULL); 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; |