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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2013-10-12 02:39:25 +0200 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-11-06 08:48:43 +0100 |
| commit | d63285e94af3ade4fa8b10b0d9a22bcf72baf2f9 (patch) | |
| tree | ea3eba620830c9eb954875e1153fc2e453b9464c /arch/x86/kernel/pvclock.c | |
| parent | kvm: optimize out smp_mb after srcu_read_unlock (diff) | |
| download | linux-d63285e94af3ade4fa8b10b0d9a22bcf72baf2f9.tar.xz linux-d63285e94af3ade4fa8b10b0d9a22bcf72baf2f9.zip | |
pvclock: detect watchdog reset at pvclock read
Implement reset of kernel watchdogs at pvclock read time. This avoids
adding special code to every watchdog.
This is possible for watchdogs which measure time based on sched_clock() or
ktime_get() variants.
Suggested by Don Zickus.
Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86/kernel/pvclock.c')
| -rw-r--r-- | arch/x86/kernel/pvclock.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index a16bae3f83b3..6279928c0a71 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -43,6 +43,13 @@ unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src) return pv_tsc_khz; } +void pvclock_touch_watchdogs(void) +{ + touch_softlockup_watchdog_sync(); + clocksource_touch_watchdog(); + rcu_cpu_stall_reset(); +} + static atomic64_t last_value = ATOMIC64_INIT(0); void pvclock_resume(void) @@ -74,6 +81,11 @@ cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) version = __pvclock_read_cycles(src, &ret, &flags); } while ((src->version & 1) || version != src->version); + if (unlikely((flags & PVCLOCK_GUEST_STOPPED) != 0)) { + src->flags &= ~PVCLOCK_GUEST_STOPPED; + pvclock_touch_watchdogs(); + } + if ((valid_flags & PVCLOCK_TSC_STABLE_BIT) && (flags & PVCLOCK_TSC_STABLE_BIT)) return ret; |