linux-kernel - Re: [PATCH V2 1/1] perf/x86: Add Intel power cstate PMUs support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 6 Aug 2015 13:16:08 -0700
From:	Stephane Eranian <eranian@...gle.com>
To:	"Liang, Kan" <kan.liang@...el.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	"mingo@...hat.com" <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V2 1/1] perf/x86: Add Intel power cstate PMUs support

On Thu, Aug 6, 2015 at 12:25 PM, Liang, Kan <kan.liang@...el.com> wrote:
>
>>
>> On Thu, Aug 6, 2015 at 11:52 AM, Liang, Kan <kan.liang@...el.com> wrote:
>> >
>> >
>> >> >> +static cpumask_t power_cstate_core_cpu_mask;
>> >> >
>> >> > That one typically does not need a cpumask.
>> >> >
>> >> You need to pick one CPU out of the multi-core. But it is for client
>> >> parts thus there is only one socket. At least this is my understanding.
>> >>
>> >
>> > CORE_C*_RESIDENCY are available for physical processor core.
>> > So logical processor in same physical processor core share the same
>> > counter.
>> > I think we need the cpumask to identify the default logical processor
>> > which do counting.
>> >
>> Did you restrict these events to system-wide mode only?
>>
Ok, so that means that your cpumask includes one HT per physical core. But then,
the result is not the simple aggregation of all the N/2 CPUs.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/