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| author | Richard Cochran <richardcochran@gmail.com> | 2014-12-21 19:47:06 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-12-30 18:29:27 -0500 |
| commit | 2eebdde6528a722fbf8e2cffcf7aa52cbb4c2de0 (patch) | |
| tree | c4b176d1e40eecb2caa00952eae95ecb2b2a046b /virt | |
| parent | f25a30be359d0535fb1c7c1619cabb0ad17cfbf1 (diff) | |
| download | linux-2eebdde6528a722fbf8e2cffcf7aa52cbb4c2de0.tar.gz linux-2eebdde6528a722fbf8e2cffcf7aa52cbb4c2de0.tar.bz2 linux-2eebdde6528a722fbf8e2cffcf7aa52cbb4c2de0.zip | |
timecounter: keep track of accumulated fractional nanoseconds
The current timecounter implementation will drop a variable amount
of resolution, depending on the magnitude of the time delta. In
other words, reading the clock too often or too close to a time
stamp conversion will introduce errors into the time values. This
patch fixes the issue by introducing a fractional nanosecond field
that accumulates the low order bits.
Reported-by: Janusz Użycki <j.uzycki@elproma.com.pl>
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/arch_timer.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 1c0772b340d8..6e54f3542126 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -152,7 +152,8 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) return; } - ns = cyclecounter_cyc2ns(timecounter->cc, cval - now); + ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask, + &timecounter->frac); timer_arm(timer, ns); } |