Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754786Ab0FNOoK (ORCPT ); Mon, 14 Jun 2010 10:44:10 -0400 Received: from one.firstfloor.org ([213.235.205.2]:36282 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752496Ab0FNOoG (ORCPT ); Mon, 14 Jun 2010 10:44:06 -0400 Date: Mon, 14 Jun 2010 16:44:03 +0200 From: Andi Kleen To: Don Zickus Cc: Hidetoshi Seto , Ingo Molnar , Huang Ying , Fr??d??ric Weisbecker , Peter Zijlstra , "H. Peter Anvin" , linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [RFC 1/3] Unified NMI delayed call mechanism Message-ID: <20100614144403.GA369@basil.fritz.box> References: <1276334896-7075-1-git-send-email-ying.huang@intel.com> <20100612102558.GA4000@elte.hu> <4C15A5D1.1040104@jp.fujitsu.com> <20100614135403.GH4894@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100614135403.GH4894@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 29 > I think the perf event subsytem can log events in NMI context already and > deliver them to userspace when the NMI is done. This is why I think Ingo > wants MCE to be updated to sit on top of the perf event subsytem to avoid > re-invent everything again. perf is not solving the problem this is trying to solve. > Then again I do not know enough about the MCE stuff to understand what you > mean when an event comes in but you can't handle it in an NMI-safe > context. An example would be helpful. At least for MCE hwpoison recovery needs to sleep and you obviously cannot sleep in NMI like context. The way it's done is to first do a self interrupt, then do a work queue wakeup and finally the sleeping operations. perf does not fit into this because it has no way to process such an event inside the kernel. Anyways this just cleans up the existing mechanism to share some code. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/