Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992782AbWJUB3j (ORCPT ); Fri, 20 Oct 2006 21:29:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992781AbWJUB3j (ORCPT ); Fri, 20 Oct 2006 21:29:39 -0400 Received: from ozlabs.org ([203.10.76.45]:33502 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S2992775AbWJUB3i (ORCPT ); Fri, 20 Oct 2006 21:29:38 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17721.30698.868001.739660@cargo.ozlabs.ibm.com> Date: Sat, 21 Oct 2006 11:29:14 +1000 From: Paul Mackerras To: Linus Torvalds Cc: Ralf Baechle , David Miller , nickpiggin@yahoo.com.au, akpm@osdl.org, linux-kernel@vger.kernel.org, anemo@mba.ocn.ne.jp, linux-arch@vger.kernel.org, schwidefsky@de.ibm.com, James.Bottomley@SteelEye.com Subject: Re: [PATCH 1/3] Fix COW D-cache aliasing on fork In-Reply-To: References: <20061020214916.GA27810@linux-mips.org> <20061020.152247.111203913.davem@davemloft.net> <20061020225118.GA30965@linux-mips.org> <20061021000609.GA32701@linux-mips.org> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 723 Lines: 19 Linus Torvalds writes: > I think (but may be mistaken) that ARM _does_ have pure virtual caches > with a process ID, but people have always ended up flushing them at > context switch simply because it just causes too much trouble. > > Sparc? VIPT too? Davem? There is one PowerPC embedded chip family, the PPC440, which has a virtual i-cache with a process ID tag. The d-cache is sane though. Of course, the i-cache being readonly means we avoid the nastier issues. Paul. - 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/