Re: [PATCH V2] x86/Hyper-V: Fix hv sched clock function return wrong time unit

[Wei Liu]

On Mon, Mar 30, 2020 at 11:05:02AM +0100, Wei Liu wrote:
> On Fri, Mar 27, 2020 at 09:53:39AM +0100, Vitaly Kuznetsov wrote:
> > Tianyu Lan <ltykernel@xxxxxxxxx> writes:
> > 
> > > From: Yubo Xie <yuboxie@xxxxxxxxxxxxx>
> > >
> > > sched clock callback should return time with nano second as unit
> > > but current hv callback returns time with 100ns. Fix it.
> > >
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Yubo Xie <yuboxie@xxxxxxxxxxxxx>
> > > Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
> > > Fixes: bd00cd52d5be ("clocksource/drivers/hyperv: Add Hyper-V specific sched clock function")
> > > ---
> > > Change since v1:
> > > 	Update fix commit number in change log. 
> > > ---
> > >  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);
> > >  }
> > >  
> > >  static struct clocksource hyperv_cs_msr = {
> > 
> > Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> 
> Queued for hyperv-fixes. Thank you both.

It appears Thomas already sent this to Linus, so I will drop this from
my branch.

Wei.

> 
> Wei.