linux-kernel - Re: [RFC PATCH 5/7] perf, x86: use the PEBS auto reload mechanism when possible

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: <20140528075937.GO11096@twins.programming.kicks-ass.net>
Date:	Wed, 28 May 2014 09:59:37 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	"Yan, Zheng" <zheng.z.yan@...el.com>
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu, eranian@...gle.com,
	ak@...ux.intel.com
Subject: Re: [RFC PATCH 5/7] perf, x86: use the PEBS auto reload mechanism
 when possible

On Wed, May 28, 2014 at 02:18:08PM +0800, Yan, Zheng wrote:
> When a fixed period is specified, this patch make perf use the PEBS
> auto reload mechanism. This makes normal profiling faster, because
> it avoids one costly MSR write in the PMI handler.
> 

You can't do this unconditionally. Like I think you mention in the next
patch, we need the PMI to fix up lots of cases.

Content of type "application/pgp-signature" skipped