Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755472AbYK0NlI (ORCPT ); Thu, 27 Nov 2008 08:41:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752177AbYK0Nky (ORCPT ); Thu, 27 Nov 2008 08:40:54 -0500 Received: from one.firstfloor.org ([213.235.205.2]:59736 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbYK0Nky (ORCPT ); Thu, 27 Nov 2008 08:40:54 -0500 Date: Thu, 27 Nov 2008 14:51:25 +0100 From: Andi Kleen To: eranian@gmail.com Cc: Thomas Gleixner , Andi Kleen , David Miller , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mingo@elte.hu, x86@kernel.org, sfr@canb.auug.org.au Subject: Re: [patch 05/24] perfmon: X86 generic code (x86) Message-ID: <20081127135125.GP6703@one.firstfloor.org> References: <7c86c4470811270209q18d4e83aq8901837159838cc4@mail.gmail.com> <20081127113115.GH6703@one.firstfloor.org> <7c86c4470811270335p2dbd61ebpe2c584e32d8b2292@mail.gmail.com> <20081127.034247.72331360.davem@davemloft.net> <20081127123811.GJ6703@one.firstfloor.org> <7c86c4470811270431n5cf1b863tc4f8c7829283e332@mail.gmail.com> <7c86c4470811270537y57577314we44d3d81b5f7d4a7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7c86c4470811270537y57577314we44d3d81b5f7d4a7@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1034 Lines: 27 On Thu, Nov 27, 2008 at 02:37:47PM +0100, stephane eranian wrote: > On Thu, Nov 27, 2008 at 2:32 PM, Thomas Gleixner wrote: > > On Thu, 27 Nov 2008, stephane eranian wrote: > >> That's true for Intel. > >> On AMD64, I think you can get at most one sample out of a irq-off > >> region using IBS. > > > > Exactly the same amount which you get with the NMI/self_IPI out of an > > irq-off region. > > > Why would you get only one sample per irq-off region if you use NMI? > I would think you could get multiple, depending on your sampling period > and the size of the region. Because of the self IPI. You would need a NMI safe queue between NMI and self IPI, but then you could as well have the same queue between NMI and process readers. -Andi -- ak@linux.intel.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/