Re: Hi, Ingo, would you please help drop the TSC MSR calibration patch

Re: Hi, Ingo, would you please help drop the TSC MSR calibration patch

[Jacob Pan]

On Mon, 11 Jul 2016 07:59:19 -0700
"Chen, Yu C" <yu.c.chen@intel.com> wrote:

> Currently it is in your x86/timer tree:
> 
> commit fc273eeef314cdaf0ac992b400d126f8184a4d1c
> Author: Len Brown <len.brown@intel.com>
> Date:   Fri Jun 17 01:22:49 2016 -0400
> 
>     x86/tsc_msr: Extend to include Intel Core Architecture
> 
> 
> Previously we found this patch might decrease the performance on
> one of our servers, due to the small gap between using old PIT
> calibration and new MSR calibration method, so we currently would
> like to hold this patch for now, until we got a clear answer from our
> architect. Would you please help revert this patch (the other patches
> are safe and can be merged), sorry for the inconvenience.
> 
I modified the subject slightly to be more specific.
Adding lkml and x86 list, and a few more people.
This commit is also affected, won't compile if we revert the one above.

37c528e... x86/tsc_msr: Fix rdmsr(MSR_PLATFORM_INFO) unsafe warning in
KVM guest

> thanks,
> Yu
> 
> 

[Jacob Pan]

Re: Hi, Ingo, would you please help drop the TSC MSR calibration patch

[Ingo Molnar]

* Jacob Pan <jacob.jun.pan@intel.com> wrote:

> On Mon, 11 Jul 2016 07:59:19 -0700
> "Chen, Yu C" <yu.c.chen@intel.com> wrote:
> 
> > Currently it is in your x86/timer tree:
> > 
> > commit fc273eeef314cdaf0ac992b400d126f8184a4d1c
> > Author: Len Brown <len.brown@intel.com>
> > Date:   Fri Jun 17 01:22:49 2016 -0400
> > 
> >     x86/tsc_msr: Extend to include Intel Core Architecture
> > 
> > 
> > Previously we found this patch might decrease the performance on
> > one of our servers, due to the small gap between using old PIT
> > calibration and new MSR calibration method, so we currently would
> > like to hold this patch for now, until we got a clear answer from our
> > architect. Would you please help revert this patch (the other patches
> > are safe and can be merged), sorry for the inconvenience.
> > 
> I modified the subject slightly to be more specific.
> Adding lkml and x86 list, and a few more people.
> This commit is also affected, won't compile if we revert the one above.
> 
> 37c528e... x86/tsc_msr: Fix rdmsr(MSR_PLATFORM_INFO) unsafe warning in
> KVM guest

Ok, I've rebased tip:x86/timers, it now includes the following commits:

ff4c86635ee1 x86/tsc: Enumerate BXT tsc_khz via CPUID
aa297292d708 x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID
02c0cd2dcf7f x86/tsc_msr: Remove irqoff around MSR-based TSC enumeration
6fcb41cdaee5 x86/tsc_msr: Add Airmont reference clock values
05680e7fa8a4 x86/tsc_msr: Correct Silvermont reference clock values
9e0cae9f6227 x86/tsc_msr: Update comments, expand definitions
14bb4e34860a x86/tsc_msr: Remove debugging messages
ba8268330dc1 x86/tsc_msr: Identify Intel-specific code
fc5f3ac24720 Revert "x86/tsc: Add missing Cherrytrail frequency to the table"

Does that work for you?

Thanks,

	Ingo

Re: Hi, Ingo, would you please help drop the TSC MSR calibration patch

[Jacob Pan]

On Mon, 11 Jul 2016 21:31:04 +0200
Ingo Molnar <mingo@kernel.org> wrote:

> 
> * Jacob Pan <jacob.jun.pan@intel.com> wrote:
> 
> > On Mon, 11 Jul 2016 07:59:19 -0700
> > "Chen, Yu C" <yu.c.chen@intel.com> wrote:
> > 
> > > Currently it is in your x86/timer tree:
> > > 
> > > commit fc273eeef314cdaf0ac992b400d126f8184a4d1c
> > > Author: Len Brown <len.brown@intel.com>
> > > Date:   Fri Jun 17 01:22:49 2016 -0400
> > > 
> > >     x86/tsc_msr: Extend to include Intel Core Architecture
> > > 
> > > 
> > > Previously we found this patch might decrease the performance on
> > > one of our servers, due to the small gap between using old PIT
> > > calibration and new MSR calibration method, so we currently would
> > > like to hold this patch for now, until we got a clear answer from
> > > our architect. Would you please help revert this patch (the other
> > > patches are safe and can be merged), sorry for the inconvenience.
> > > 
> > I modified the subject slightly to be more specific.
> > Adding lkml and x86 list, and a few more people.
> > This commit is also affected, won't compile if we revert the one
> > above.
> > 
> > 37c528e... x86/tsc_msr: Fix rdmsr(MSR_PLATFORM_INFO) unsafe warning
> > in KVM guest
> 
> Ok, I've rebased tip:x86/timers, it now includes the following
> commits:
> 
> ff4c86635ee1 x86/tsc: Enumerate BXT tsc_khz via CPUID
> aa297292d708 x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID
> 02c0cd2dcf7f x86/tsc_msr: Remove irqoff around MSR-based TSC
> enumeration 6fcb41cdaee5 x86/tsc_msr: Add Airmont reference clock
> values 05680e7fa8a4 x86/tsc_msr: Correct Silvermont reference clock
> values 9e0cae9f6227 x86/tsc_msr: Update comments, expand definitions
> 14bb4e34860a x86/tsc_msr: Remove debugging messages
> ba8268330dc1 x86/tsc_msr: Identify Intel-specific code
> fc5f3ac24720 Revert "x86/tsc: Add missing Cherrytrail frequency to
> the table"
> 
> Does that work for you?
> 
works for me but Yu has to confirm.

> Thanks,
> 
> 	Ingo

RE: Hi, Ingo, would you please help drop the TSC MSR calibration patch

[Chen, Yu C]

Hi, 
> -----Original Message-----
> From: Pan, Jacob jun
> Sent: Tuesday, July 12, 2016 5:19 AM
> To: Ingo Molnar
> Cc: Chen, Yu C; 'Len Brown'; Jacob Pan; H. Peter Anvin; Peter Zijlstra;
> x86@kernel.org; linux-kernel@vger.kernel.org; Pan, Jacob jun
> Subject: Re: Hi, Ingo, would you please help drop the TSC MSR calibration patch
> 
> On Mon, 11 Jul 2016 21:31:04 +0200
> Ingo Molnar <mingo@kernel.org> wrote:
> 
> >
> > * Jacob Pan <jacob.jun.pan@intel.com> wrote:
> >
> > > On Mon, 11 Jul 2016 07:59:19 -0700
> > > "Chen, Yu C" <yu.c.chen@intel.com> wrote:
> > >
> > > > Currently it is in your x86/timer tree:
> > > >
> > > > commit fc273eeef314cdaf0ac992b400d126f8184a4d1c
> > > > Author: Len Brown <len.brown@intel.com>
> > > > Date:   Fri Jun 17 01:22:49 2016 -0400
> > > >
> > > >     x86/tsc_msr: Extend to include Intel Core Architecture
> > > >
> > > >
> > > > Previously we found this patch might decrease the performance on
> > > > one of our servers, due to the small gap between using old PIT
> > > > calibration and new MSR calibration method, so we currently would
> > > > like to hold this patch for now, until we got a clear answer from
> > > > our architect. Would you please help revert this patch (the other
> > > > patches are safe and can be merged), sorry for the inconvenience.
> > > >
> > > I modified the subject slightly to be more specific.
> > > Adding lkml and x86 list, and a few more people.
> > > This commit is also affected, won't compile if we revert the one
> > > above.
> > >
> > > 37c528e... x86/tsc_msr: Fix rdmsr(MSR_PLATFORM_INFO) unsafe warning
> > > in KVM guest
> >
> > Ok, I've rebased tip:x86/timers, it now includes the following
> > commits:
> >
> > ff4c86635ee1 x86/tsc: Enumerate BXT tsc_khz via CPUID
> > aa297292d708 x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID
> > 02c0cd2dcf7f x86/tsc_msr: Remove irqoff around MSR-based TSC
> > enumeration 6fcb41cdaee5 x86/tsc_msr: Add Airmont reference clock
> > values 05680e7fa8a4 x86/tsc_msr: Correct Silvermont reference clock
> > values 9e0cae9f6227 x86/tsc_msr: Update comments, expand definitions
> > 14bb4e34860a x86/tsc_msr: Remove debugging messages
> > ba8268330dc1 x86/tsc_msr: Identify Intel-specific code
> > fc5f3ac24720 Revert "x86/tsc: Add missing Cherrytrail frequency to the
> > table"
> >
> > Does that work for you?
> >
> works for me but Yu has to confirm.
> 
Confirmed, thanks!

thanks,
Yu