linux-kernel - Re: [RFC PATCH] perf: Add PERF_RECORD_SWITCH to indicate context switches

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]

Message-ID: <1434117172.1484.14.camel@arm.com>
Date:	Fri, 12 Jun 2015 14:52:52 +0100
From:	Pawel Moll <pawel.moll@....com>
To:	Adrian Hunter <adrian.hunter@...el.com>
Cc:	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andi Kleen <ak@...ux.intel.com>,
	Ingo Molnar <mingo@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Jiri Olsa <jolsa@...hat.com>,
	Stephane Eranian <eranian@...gle.com>,
	"mathieu.poirier@...aro.org" <mathieu.poirier@...aro.org>
Subject: Re: [RFC PATCH] perf: Add PERF_RECORD_SWITCH to indicate context
 switches

On Fri, 2015-06-12 at 14:28 +0100, Pawel Moll wrote:
> On Fri, 2015-06-12 at 14:15 +0100, Adrian Hunter wrote:
> > >>>> all 3 are already part of sample_id.
> > >>>
> > >>> You have to decide whether you expect to be able to use an event without
> > >>> sample_id. MMAP and MMAP2 both have pid, tid which are in sample_id, LOST
> > >>> has id, EXIT and FORK have time, all of the THROTTLE/UNTHROTTLE members are
> > >>> in sample_id etc. So it currently looks like we expect to be able to use an
> > >>> event without requiring sample_id.
> > > 
> > > The fact that there is this duplication is because sample_id_all came
> > > after those events, but this new one being proposed doesn't have to do
> > > it :-)
> > 
> > Thanks, that's clear then.  There will just need to be a flag to indicate
> > whether it is scheduling in or out.
> 
> Just a thought: wouldn't it be good to know what CPU have we been
> scheduled from/to? This kind of information would be especially valuable
> in heterogeneous systems.

Of course, cpu is a part of sample_id as well. I'm sorted out then :-)

Pawel

--
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/