linux-kernel - Re: [PATCH -tip] perf, x86: Make a second write to performance counter if needed

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: <1275988719.17004.110.camel@minggr.sh.intel.com>
Date:	Tue, 08 Jun 2010 17:18:39 +0800
From:	Lin Ming <ming.m.lin@...el.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Cyrill Gorcunov <gorcunov@...nvz.org>, Ingo Molnar <mingo@...e.hu>,
	Robert Richter <robert.richter@....com>,
	LKML <linux-kernel@...r.kernel.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Frédéric Weisbecker <fweisbec@...il.com>
Subject: Re: [PATCH -tip] perf, x86: Make a second write to performance
 counter if needed

On Mon, 2010-06-07 at 17:48 +0800, Peter Zijlstra wrote:
> On Thu, 2010-06-03 at 01:23 +0400, Cyrill Gorcunov wrote:
> > On Netburst PMU we need a second write to a performance counter
> > due to cpu erratum.
> > 
> > A simple flag test instead of alternative instructions was choosen
> > because wrmsrl is already a macro and if virtualization is turned
> > on will need an additional wrapper call which is more expencise.
> > 
> > nb: we should propably switch to jump-labels as only this facility
> > reach the mainline.
> 
> OK. Thanks Cyrill.


I tested this patch and it works well for pre-defined events.

Lin Ming

--
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/