Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756767AbYHLAkV (ORCPT ); Mon, 11 Aug 2008 20:40:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753915AbYHLAkE (ORCPT ); Mon, 11 Aug 2008 20:40:04 -0400 Received: from rhun.apana.org.au ([64.62.148.172]:43045 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751932AbYHLAkD (ORCPT ); Mon, 11 Aug 2008 20:40:03 -0400 Date: Tue, 12 Aug 2008 08:39:38 +0800 From: Herbert Xu To: Suresh Siddha Cc: "H. Peter Anvin" , Ingo Molnar , Wolfgang Walter , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "viro@ZenIV.linux.org.uk" , "vegard.nossum@gmail.com" , Thomas Gleixner Subject: Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes Message-ID: <20080812003938.GC18230@gondor.apana.org.au> References: <20080809143727.GA30499@gondor.apana.org.au> <200808091757.32999.wolfgang.walter@stwm.de> <489DC15D.9070308@zytor.com> <20080809185224.GH13158@linux-os.sc.intel.com> <20080809193724.GJ13158@linux-os.sc.intel.com> <20080810030521.GA2332@gondor.apana.org.au> <20080811190131.GL13158@linux-os.sc.intel.com> <20080811192203.GC12788@elte.hu> <48A0920B.30306@zytor.com> <20080811201901.GN13158@linux-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080811201901.GN13158@linux-os.sc.intel.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1053 Lines: 25 On Mon, Aug 11, 2008 at 01:19:01PM -0700, Suresh Siddha wrote: . > we can't unconditionally do clts() in the process context. We have > to disable pre-emption to avoid interactions with context switch and > lazy restore. So there will be RT latency issues aswell. Yes disabling preemption is the real killer. This is just a quick band-aid. Longer term we should add a task flag that indicates the task is currently doing kernel FPU which will tell the scheduler to clear TS the next time it's run. That way we won't need to disable preemtion or pollute the user task's FPU used state. Thanks, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- 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/