Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758343AbYHICE2 (ORCPT ); Fri, 8 Aug 2008 22:04:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754216AbYHICEQ (ORCPT ); Fri, 8 Aug 2008 22:04:16 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59488 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754192AbYHICEP (ORCPT ); Fri, 8 Aug 2008 22:04:15 -0400 Message-ID: <489CF9EC.5050109@zytor.com> Date: Fri, 08 Aug 2008 18:59:08 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Herbert Xu CC: Suresh Siddha , Wolfgang Walter , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ingo Molnar , viro@ZenIV.linux.org.uk, vegard.nossum@gmail.com Subject: Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes References: <200807171653.59177.wolfgang.walter@stwm.de> <20080806201401.GA607@linux-os.sc.intel.com> <200808071823.02364.wolfgang.walter@stwm.de> <200808081236.55172.wolfgang.walter@stwm.de> <20080808185356.GC607@linux-os.sc.intel.com> <489C97FB.2030408@zytor.com> <20080809014925.GA26529@gondor.apana.org.au> In-Reply-To: <20080809014925.GA26529@gondor.apana.org.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 32 Herbert Xu wrote: > On Fri, Aug 08, 2008 at 12:01:15PM -0700, H. Peter Anvin wrote: >> It's technically overkill, if (and only if!) these instructions don't >> actually touch the SSE state (most likely they're using the SSE >> pipeline, and need this stuff to deal with power management issues.) > > Yes the PadLock uses the SSE pipeline, but doesn't touch any > of the state. And yet it requires all the settings that goes along with holding the SSE state. Really crap design, unfortunately. >> However, overkill is a good way to make sure something is dead. >> Applying the patch will make sure we fix the regression, and we can >> worry about optimizing this further post-2.6.27. > > Do we really need the FPU changes right now? I'd prefer for that > to be backed out until a proper solution is found. Disabling > preemption around crypto is really bad for scheduling latency. I hate to say it, but given the relative marketshare, we should disable Padlock instead. This is part of the pain of being a minority architecture. -hpa -- 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/