> -----Original Message----- > From: Thomas Gleixner [mailto:tglx@xxxxxxxxxxxxx] > Sent: Saturday, July 4, 2015 1:11 AM > To: KY Srinivasan > Cc: x86@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; > apw@xxxxxxxxxxxxx; jasowang@xxxxxxxxxx; Vivek Yadav > Subject: Re: [PATCH 1/1] x86: Hyper-V: Mark the Hyper-V clocksource as > being high resolution > > On Fri, 3 Jul 2015, K. Y. Srinivasan wrote: > > From: Vivek yadav <vyadav@xxxxxxxxxxxxx> > > > > By design, alternative clock sources listed are based on the resolution of > > current clock source. Once you set a high resolution clock, > > only high resolution sources are returned. > > Mark Hyper-V clock source as a high resolution clock source. > > > > Signed-off-by: Vivek yadav <vyadav@xxxxxxxxxxxxx> > > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > > --- > > arch/x86/kernel/cpu/mshyperv.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/mshyperv.c > b/arch/x86/kernel/cpu/mshyperv.c > > index 9b5d7b5..0e507a0 100644 > > --- a/arch/x86/kernel/cpu/mshyperv.c > > +++ b/arch/x86/kernel/cpu/mshyperv.c > > @@ -151,7 +151,8 @@ static struct clocksource hyperv_cs = { > > .rating = 400, /* use this when running on Hyperv*/ > > .read = read_hv_clock, > > .mask = CLOCKSOURCE_MASK(64), > > - .flags = CLOCK_SOURCE_IS_CONTINUOUS, > > + .flags = CLOCK_SOURCE_IS_CONTINUOUS | > > + CLOCK_SOURCE_VALID_FOR_HRES, > > No, this is wrong. The CLOCK_SOURCE_VALID_FOR_HRES flag is managed by > the core code and set when a clocksource fulfils the criteria. > > The changelog above is not explaining what problem you are trying to > solve. > I think the problem Vivek was trying to solve is that after the Hyper-V clocxk was installed, if the user switched to another clocksource, say tsc, the hyper-V clock source would not listed. I will investigate this further and let you know. Thanks for the feedback. Regards, K. Y > > tglx > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
