Hi Vitaly: Thanks for your review.
On 3/24/2020 11:49 PM, Vitaly Kuznetsov wrote:
Yubo Xie ltykernel@gmail.com writes:
sched clock callback should return time with nano second as unit but current hv callback returns time with 100ns. Fix it.
Cc: stable@vger.kernel.org Signed-off-by: Yubo Xie yuboxie@microsoft.com Signed-off-by: Tianyu Lan Tianyu.Lan@microsoft.com Fixes: adb87ff4f96c ("clocksource/drivers/hyperv: Allocate Hyper-V TSC page statically")
I don't think this is the right commit to reference,
commit bd00cd52d5be655a2f217e2ed74b91a71cb2b14f Author: Tianyu Lan Tianyu.Lan@microsoft.com Date: Wed Aug 14 20:32:16 2019 +0800
clocksource/drivers/hyperv: Add Hyper-V specific sched clock functionlooks like the one.
Sorry. You are right. Will update in the next version.
drivers/clocksource/hyperv_timer.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 9d808d595ca8..662ed978fa24 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -343,7 +343,8 @@ static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg) static u64 read_hv_sched_clock_tsc(void) {
- return read_hv_clock_tsc() - hv_sched_clock_offset;
- return (read_hv_clock_tsc() - hv_sched_clock_offset)
* (NSEC_PER_SEC / HV_CLOCK_HZ);static void suspend_hv_clock_tsc(struct clocksource *arg) @@ -398,7 +399,8 @@ static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg) static u64 read_hv_sched_clock_msr(void) {
- return read_hv_clock_msr() - hv_sched_clock_offset;
- return (read_hv_clock_msr() - hv_sched_clock_offset)
* (NSEC_PER_SEC / HV_CLOCK_HZ);kvmclock seems to have the same (pre-patch) code ...
kvm sched clock gets time from pvclock_clocksource_read() and the time unit is nanosecond. So there is such issue in KVM code.
static struct clocksource hyperv_cs_msr = {