RE: [PATCH V3 2/4] x86/resctrl: Enumerate per-thread MBA

Babu Moger
2020-05-14T20:41:44Z

> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@intel.com>
> Sent: Thursday, May 14, 2020 3:12 PM
> To: Moger, Babu <Babu.Moger@amd.com>; tglx@linutronix.de;
> fenghua.yu@intel.com; bp@alien8.de; tony.luck@intel.com
> Cc: kuo-lang.tseng@intel.com; ravi.v.shankar@intel.com; mingo@redhat.com;
> hpa@zytor.com; x86@kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V3 2/4] x86/resctrl: Enumerate per-thread MBA
>
> Hi Babu,
>
> On 5/14/2020 12:04 PM, Babu Moger wrote:
> >
> >
> >> -----Original Message-----
> >> From: Reinette Chatre <reinette.chatre@intel.com>
> >> Sent: Wednesday, May 6, 2020 6:50 PM
> >> To: tglx@linutronix.de; fenghua.yu@intel.com; bp@alien8.de;
> >> tony.luck@intel.com
> >> Cc: kuo-lang.tseng@intel.com; ravi.v.shankar@intel.com;
> mingo@redhat.com;
> >> Moger, Babu <Babu.Moger@amd.com>; hpa@zytor.com; x86@kernel.org;
> >> linux-kernel@vger.kernel.org; Reinette Chatre <reinette.chatre@intel.com>
> >> Subject: [PATCH V3 2/4] x86/resctrl: Enumerate per-thread MBA
> >>
> >> From: Fenghua Yu <fenghua.yu@intel.com>
> >>
>
> ...
>
> >> diff --git a/arch/x86/kernel/cpu/scattered.c
> b/arch/x86/kernel/cpu/scattered.c
> >> index 62b137c3c97a..bccfc9ff3cc1 100644
> >> --- a/arch/x86/kernel/cpu/scattered.c
> >> +++ b/arch/x86/kernel/cpu/scattered.c
> >> @@ -35,6 +35,7 @@ static const struct cpuid_bit cpuid_bits[] = {
> >> { X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1
> >> },
> >> { X86_FEATURE_CDP_L2, CPUID_ECX, 2, 0x00000010, 2
> >> },
> >> { X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 },
> >> + { X86_FEATURE_PER_THREAD_MBA, CPUID_ECX, 0, 0x00000010, 3
> >> },
> >
> > This is a CPUID feature. You can actually detect this feature without
> > checking vendor model in patch @1. This patch looks good to me.
> >
>
> This feature is different from the feature introduced in patch 1.

Ok. I mis-understood that.