RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes

From	Shivappa Vikas <vikas.shivappa@intel.com>
Newsgroups	linux.kernel
Subject	RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes
Date	2017-02-02 19:00 +0100
Message-ID	<t6tPR-77C-41@gated-at.bofh.it> (permalink)
References	(4 earlier) <t1NPc-3oi-15@gated-at.bofh.it> <t2JTc-59S-17@gated-at.bofh.it> <t69o5-26I-15@gated-at.bofh.it> <t6dBo-4UR-9@gated-at.bofh.it> <t6enL-5rr-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw


On Wed, 1 Feb 2017, Yu, Fenghua wrote:

>> From: Andi Kleen [mailto:andi@firstfloor.org]
>> "Luck, Tony" <tony.luck@intel.com> writes:
>>> 9)	Measure per logical CPU (pick active RMID in same precedence for
>> task/cpu as CAT picks CLOSID)
>>> 10)	Put multiple CPUs into a group
>>
>> I'm not sure this is a real requirement. It's just an optimization, right? If you
>> can assign policies to threads, you can implicitly set it per CPU through affinity
>> (or the other way around).
>> The only benefit would be possibly less context switch overhead, but if all
>> the thread (including idle) assigned to a CPU have the same policy it would
>> have the same results.
>>
>> I suspect dropping this would likely simplify the interface significantly.
>
> Assigning a pid P to a CPU and monitoring the P don't count all events happening on the CPU.
> Other processes/threads (e.g. kernel threads) than the assigned P can run on the CPU.
> Monitoring P assigned to the CPU is not equal to monitoring the CPU in a lot cases.

This matches the use case where a bunch of real time tasks which have no CLOS 
id(kernel threads or others in root group) would want to run exclusively on a 
cpu and are configured so. If any other tasks run there from other class of 
service we dont want to pullute the cache - hence choose their own CLOSId.

Now in order to measure this RMIds need to match the same policy as CAT.

Thanks,
Vikas

>
> Thanks.
>
> -Fenghua
>

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-01 21:10 +0100
  Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-02 00:20 +0100
    RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-02 18:40 +0100
    RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-02 20:40 +0100
      RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Shivappa Vikas <vikas.shivappa@intel.com> - 2017-02-02 21:20 +0100
      Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-02 21:30 +0100
        Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-03 00:50 +0100
          Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-03 02:50 +0100
            Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-03 03:20 +0100
              Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-03 19:00 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-03 22:10 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-03 23:30 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Stephane Eranian <eranian@google.com> - 2017-02-07 09:10 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-07 20:10 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Stephane Eranian <eranian@google.com> - 2017-02-08 22:40 +0100
                Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Shivappa Vikas <vikas.shivappa@intel.com> - 2017-02-07 21:30 +0100
    RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-06 20:00 +0100
    RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-06 22:30 +0100
      RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Shivappa Vikas <vikas.shivappa@intel.com> - 2017-02-06 22:40 +0100
        Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-06 22:50 +0100
      Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-06 23:20 +0100
        RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Luck, Tony" <tony.luck@intel.com> - 2017-02-07 00:30 +0100
          Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-07 01:40 +0100
  Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Andi Kleen <andi@firstfloor.org> - 2017-02-02 01:40 +0100
    Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Andi Kleen <andi@firstfloor.org> - 2017-02-02 02:20 +0100
    Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes David Carrillo-Cisneros <davidcc@google.com> - 2017-02-02 02:20 +0100
    RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes "Yu, Fenghua" <fenghua.yu@intel.com> - 2017-02-02 02:30 +0100
      RE: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes Shivappa Vikas <vikas.shivappa@intel.com> - 2017-02-02 19:00 +0100

csiph-web