[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <MW3PR12MB45536DBD37AF763C642DF39695489@MW3PR12MB4553.namprd12.prod.outlook.com>
Date: Fri, 16 Sep 2022 20:19:54 +0000
From: "Moger, Babu" <Babu.Moger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>,
"corbet@....net" <corbet@....net>,
"tglx@...utronix.de" <tglx@...utronix.de>,
"mingo@...hat.com" <mingo@...hat.com>,
"bp@...en8.de" <bp@...en8.de>
CC: "fenghua.yu@...el.com" <fenghua.yu@...el.com>,
"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
"x86@...nel.org" <x86@...nel.org>, "hpa@...or.com" <hpa@...or.com>,
"paulmck@...nel.org" <paulmck@...nel.org>,
"akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
"quic_neeraju@...cinc.com" <quic_neeraju@...cinc.com>,
"rdunlap@...radead.org" <rdunlap@...radead.org>,
"damien.lemoal@...nsource.wdc.com" <damien.lemoal@...nsource.wdc.com>,
"songmuchun@...edance.com" <songmuchun@...edance.com>,
"peterz@...radead.org" <peterz@...radead.org>,
"jpoimboe@...nel.org" <jpoimboe@...nel.org>,
"pbonzini@...hat.com" <pbonzini@...hat.com>,
"chang.seok.bae@...el.com" <chang.seok.bae@...el.com>,
"pawan.kumar.gupta@...ux.intel.com"
<pawan.kumar.gupta@...ux.intel.com>,
"jmattson@...gle.com" <jmattson@...gle.com>,
"daniel.sneddon@...ux.intel.com" <daniel.sneddon@...ux.intel.com>,
"Das1, Sandipan" <Sandipan.Das@....com>,
"tony.luck@...el.com" <tony.luck@...el.com>,
"james.morse@....com" <james.morse@....com>,
"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"bagasdotme@...il.com" <bagasdotme@...il.com>,
"eranian@...gle.com" <eranian@...gle.com>
Subject: RE: [PATCH v4 05/13] x86/cpufeatures: Add Bandwidth Monitoring Event
Configuration feature flag
[AMD Official Use Only - General]
Hi Reinette,
> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@...el.com>
> Sent: Friday, September 16, 2022 10:55 AM
> To: Moger, Babu <Babu.Moger@....com>; corbet@....net;
> tglx@...utronix.de; mingo@...hat.com; bp@...en8.de
> Cc: fenghua.yu@...el.com; dave.hansen@...ux.intel.com; x86@...nel.org;
> hpa@...or.com; paulmck@...nel.org; akpm@...ux-foundation.org;
> quic_neeraju@...cinc.com; rdunlap@...radead.org;
> damien.lemoal@...nsource.wdc.com; songmuchun@...edance.com;
> peterz@...radead.org; jpoimboe@...nel.org; pbonzini@...hat.com;
> chang.seok.bae@...el.com; pawan.kumar.gupta@...ux.intel.com;
> jmattson@...gle.com; daniel.sneddon@...ux.intel.com; Das1, Sandipan
> <Sandipan.Das@....com>; tony.luck@...el.com; james.morse@....com;
> linux-doc@...r.kernel.org; linux-kernel@...r.kernel.org;
> bagasdotme@...il.com; eranian@...gle.com
> Subject: Re: [PATCH v4 05/13] x86/cpufeatures: Add Bandwidth Monitoring
> Event Configuration feature flag
>
> Hi Babu,
>
> On 9/7/2022 11:00 AM, Babu Moger wrote:
> > Newer AMD processors support the new feature Bandwidth Monitoring
> > Event Configuration (BMEC).
> >
> > Support of this feature is available via CPUID Fn8000_0020_EBX_x0 (ECX=0).
> > Bits Field Name Description
> > 3 EVT_CFG Bandwidth Monitoring Event Configuration (BMEC)
> >
> > Currently, the bandwidth monitoring events mbm_total_bytes and
> > mbm_local_bytes are set to count all the total and local reads/writes
> > respectively. With the introduction of SLOW memory, the two counters
> > are
>
> Why is SLOW in caps?
Will fix it.
>
> > not enough to count all the different types of memory events. With the
> > feature BMEC, the users have the option to configure mbm_total_bytes
> > and mbm_local_bytes to count the specific type of events.
> >
> > Each BMEC event has a configuration MSR, QOS_EVT_CFG (0x000_0400h +
> > EventID) which contains one field for each Bandwidth Type that can be
> > used to configure the bandwidth event to track any combination of
> > supported bandwidth types. The event will count requests from every
> > Bandwidth Type bit that is set in the corresponding configuration register.
> >
> > Following are the types of events supported:
> >
> > ==== ========================================================
> > Bits Description
> > ==== ========================================================
> > 6 Dirty Victims from the QOS domain to all types of memory
> > 5 Reads to slow memory in the non-local NUMA domain
> > 4 Reads to slow memory in the local NUMA domain
> > 3 Non-temporal writes to non-local NUMA domain
> > 2 Non-temporal writes to local NUMA domain
> > 1 Reads to memory in the non-local NUMA domain
> > 0 Reads to memory in the local NUMA domain
> > ==== ========================================================
> >
> > By default, the mbm_total_bytes configuration is set to 0x7F to count
> > all the event types and the mbm_local_bytes configuration is set to
> > 0x15 to count all the local memory events.
> >
> > Feature description is available in the specification, "AMD64
> > Technology Platform Quality of Service Extensions, Revision: 1.03
> > Publication # 56375
> > Revision: 1.03 Issue Date: February 2022".
> >
> > Link:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.
> > amd.com%2Fen%2Fsupport%2Ftech-docs%2Famd64-technology-platform-
> quality
> > -service-
> extensions&data=05%7C01%7Cbabu.moger%40amd.com%7C5ba4a608
> >
> edb04202be2708da97fbe2df%7C3dd8961fe4884e608e11a82d994e183d%7C0%
> 7C0%7C
> >
> 637989405343884737%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMD
> AiLCJQIjo
> >
> iV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdat
> a=hoyj
> > zeINRtp1n%2FWsG0MHxzmQ8aLdDV4V03xlJVsNRv8%3D&reserved=0
> > Link:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugz
> >
> illa.kernel.org%2Fshow_bug.cgi%3Fid%3D206537&data=05%7C01%7Cbab
> u.m
> >
> oger%40amd.com%7C5ba4a608edb04202be2708da97fbe2df%7C3dd8961fe488
> 4e608e
> >
> 11a82d994e183d%7C0%7C0%7C637989405343884737%7CUnknown%7CTWFpb
> GZsb3d8ey
> >
> JWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7
> C300
> >
> 0%7C%7C%7C&sdata=n0gR1mooP9QuEzhrvXrvPaateof4XrBABrAoK5N8e8
> o%3D&am
> > p;reserved=0
> > Signed-off-by: Babu Moger <babu.moger@....com>
> > Reviewed-by: Ingo Molnar <mingo@...nel.org>
> > ---
> > arch/x86/include/asm/cpufeatures.h | 1 +
> > arch/x86/kernel/cpu/scattered.c | 1 +
> > 2 files changed, 2 insertions(+)
> >
> > diff --git a/arch/x86/include/asm/cpufeatures.h
> > b/arch/x86/include/asm/cpufeatures.h
> > index 1815435c9c88..a4ee02a56d54 100644
> > --- a/arch/x86/include/asm/cpufeatures.h
> > +++ b/arch/x86/include/asm/cpufeatures.h
> > @@ -305,6 +305,7 @@
> > #define X86_FEATURE_USE_IBPB_FW (11*32+16) /* "" Use IBPB
> during runtime firmware calls */
> > #define X86_FEATURE_RSB_VMEXIT_LITE (11*32+17) /* "" Fill RSB on
> VM exit when EIBRS is enabled */
> > #define X86_FEATURE_SMBA (11*32+18) /* SLOW Memory
> Bandwidth Allocation */
> > +#define X86_FEATURE_BMEC (11*32+18) /* AMD
> Bandwidth Monitoring Event Configuration (BMEC) */
>
> (numbering issue has already been discussed)
Yes.
>
> >
> > /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
> > #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI
> instructions */
> > diff --git a/arch/x86/kernel/cpu/scattered.c
> > b/arch/x86/kernel/cpu/scattered.c index 885ecf46abb2..7981df0b910e
> > 100644
> > --- a/arch/x86/kernel/cpu/scattered.c
> > +++ b/arch/x86/kernel/cpu/scattered.c
> > @@ -45,6 +45,7 @@ static const struct cpuid_bit cpuid_bits[] = {
> > { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
> > { X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 },
> > { X86_FEATURE_SMBA, CPUID_EBX, 2, 0x80000020, 0 },
> > + { X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 },
> > { X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 },
> > { 0, 0, 0, 0, 0 }
> > };
> >
> >
>
> Similar to previous - please use same coding style as area being changed.
Sure.
>
> Is there a feature dependency (cpuid_deps[]) on X86_FEATURE_CQM_LLC
> needed?
Good catch.. Yes. Its needed. Will fix it.
Thanks
Babu
Powered by blists - more mailing lists