linux-kernel - Re: [PATCH 4/7] perf/x86-ibs: Add support for IBS pseudo events

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: <1336405911.27020.70.camel@laptop>
Date:	Mon, 07 May 2012 17:51:51 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Robert Richter <robert.richter@....com>
Cc:	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Ingo Molnar <mingo@...nel.org>,
	Stephane Eranian <eranian@...gle.com>,
	Jiri Olsa <jolsa@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/7] perf/x86-ibs: Add support for IBS pseudo events

On Mon, 2012-05-07 at 17:44 +0200, Robert Richter wrote:
> On 07.05.12 15:03:02, Peter Zijlstra wrote:
> > On Wed, 2012-05-02 at 20:26 +0200, Robert Richter wrote:
> > > +enum ibs_filter_type {
> > > +       IBS_NO_FILTER           = 0,
> > > +       IBS_MATCH_FILTER        = 1,
> > > +       IBS_ANY_SET_FILTER      = 2,
> > > +       IBS_PSEUDO_EVENT        = 0x0F,
> > > +};
> > 
> > I don't get how those pseudo events work, AFAIKT IBS_PSEUDO_EVENT causes
> > one to loose all events since it does have a filter set but fails the
> > filter and thus we skip the call to perf_event_overflow().
> 
> You periodically (fix clk cycles or number of micro-ops) trigger IBS
> samples and afterwards analyses the samples for certain filter rules
> (see rule description in pmu-ibs.c). 

But IBS_PSEUDO_EVENT will fail all filter test and you'll end up with
exactly 0 samples. Still somewhat confused..

--
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/