From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e35.co.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 2CFEEDDE44 for ; Thu, 9 Aug 2007 02:00:34 +1000 (EST) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e35.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l78G0Wtv022028 for ; Wed, 8 Aug 2007 12:00:32 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.4) with ESMTP id l78G0VmW254850 for ; Wed, 8 Aug 2007 10:00:31 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l78G0VNp021443 for ; Wed, 8 Aug 2007 10:00:31 -0600 Date: Wed, 8 Aug 2007 11:00:29 -0500 From: Josh Boyer To: Kumar Gala Subject: Re: Fix small race in 44x tlbie function Message-ID: <20070808110029.43c110ef@weaponx.rchland.ibm.com> In-Reply-To: References: <20070807042050.GJ13522@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linuxppc-dev@ozlabs.org, Volkmar Uhlig , Paul Mackerras , Todd Inglett , David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 8 Aug 2007 10:20:45 -0500 Kumar Gala wrote: > > On Aug 6, 2007, at 11:20 PM, David Gibson wrote: > > > The 440 family of processors don't have a tlbie instruction. So, we > > implement TLB invalidates by explicitly searching the TLB with tlbsx., > > then clobbering the relevant entry, if any. Unfortunately the PID for > > the search needs to be stored in the MMUCR register, which is also > > used by the TLB miss handler. Interrupts were enabled in _tlbie(), so > > an interrupt between loading the MMUCR and the tlbsx could cause > > incorrect search results, and thus a failure to invalide TLB entries > > which needed to be invalidated. > > > > This patch fixes the problem in both arch/ppc and arch/powerpc by > > inhibiting interrupts (even critical and debug interrupts) across the > > relevant instructions. > > > > Signed-off-by: David Gibson > > --- > > Paul, this one's a bugfix, which I think should go into 2.6.23. > > Did you actually see this happen? Yes. josh