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| author | Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> | 2010-10-26 03:53:46 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-11-28 11:33:20 +0300 |
| commit | e7a3481c0246c8e45e79c629efd63b168e91fcda (patch) | |
| tree | 34886006eaa53a91e60ce4f82e1d91c916ef345e /arch/x86 | |
| parent | 0f639a3c5ca63dd76ee07de9b02ebf0178ce9a17 (diff) | |
| download | linux-e7a3481c0246c8e45e79c629efd63b168e91fcda.tar.xz | |
x86/pvclock: Zero last_value on resume
If the guest domain has been suspend/resumed or migrated, then the
system clock backing the pvclock clocksource may revert to a smaller
value (ie, can be non-monotonic across the migration/save-restore).
Make sure we zero last_value in that case so that the domain
continues to see clock updates.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pvclock.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/pvclock.c | 5 | ||||
| -rw-r--r-- | arch/x86/xen/time.c | 2 |
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 7f7e577a0e39..31d84acc1512 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -11,6 +11,7 @@ unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); void pvclock_read_wallclock(struct pvclock_wall_clock *wall, struct pvclock_vcpu_time_info *vcpu, struct timespec *ts); +void pvclock_resume(void); /* * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 008b91eefa18..42eb3300dfc6 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -83,6 +83,11 @@ unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src) static atomic64_t last_value = ATOMIC64_INIT(0); +void pvclock_resume(void) +{ + atomic64_set(&last_value, 0); +} + cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) { struct pvclock_shadow_time shadow; diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index b2bb5aa3b054..5da5e53fb94c 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -426,6 +426,8 @@ void xen_timer_resume(void) { int cpu; + pvclock_resume(); + if (xen_clockevent != &xen_vcpuop_clockevent) return; |