From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes Date: Fri, 08 Aug 2008 12:01:15 -0700 Message-ID: <489C97FB.2030408@zytor.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Wolfgang Walter , Herbert Xu , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ingo Molnar , viro@ZenIV.linux.org.uk, vegard.nossum@gmail.com To: Suresh Siddha Return-path: Received: from terminus.zytor.com ([198.137.202.10]:43872 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759445AbYHHTIC (ORCPT ); Fri, 8 Aug 2008 15:08:02 -0400 In-Reply-To: <20080808185356.GC607@linux-os.sc.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: Suresh Siddha wrote: > > I propose to go with wolf's patch which add's kernel_fpu_begin() and > kernel_fpu_end() around these instructions. This is the correct fix > (unless there is something wrong in my above understanding). > 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.) 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. -hpa