linux-kernel - Re: perf: odd event scheduling issue

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: <20150520152534.GJ18673@twins.programming.kicks-ass.net>
Date:	Wed, 20 May 2015 17:25:34 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Vince Weaver <vincent.weaver@...ne.edu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Stephane Eranian <eranian@...gle.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Jiri Olsa <jolsa@...hat.com>, Ingo Molnar <mingo@...hat.com>,
	Paul Mackerras <paulus@...ba.org>
Subject: Re: perf: odd event scheduling issue

On Wed, May 20, 2015 at 03:52:09PM +0200, Peter Zijlstra wrote:
> >     
> >     This patch limits the number of counters available to each CPU when
> >     the HT bug workaround is enabled.
> >     
> >     This is necessary to avoid situation of counter starvation. Such can
> >     arise from configuration where one HT thread, HT0, is using all 4 counters
> >     with corrupting events which require exclusion the the sibling HT, HT1.
> >     

> 
> OK, so if you have the watchdog enabled, that's 1 event, and having a
> max of 2 GP events, adding another 2 events is fail.

Hmm, so we count all events, including those scheduled on fixed purpose
counters.

Lemme see if I can cure that.
--
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/