From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23232 invoked by alias); 26 Oct 2007 20:41:36 -0000 Received: (qmail 23224 invoked by uid 22791); 26 Oct 2007 20:41:35 -0000 X-Spam-Check-By: sourceware.org Received: from e31.co.us.ibm.com (HELO e31.co.us.ibm.com) (32.97.110.149) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 26 Oct 2007 20:41:31 +0000 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e31.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l9QKfTXE031248 for ; Fri, 26 Oct 2007 16:41:29 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l9QKfS6j103482 for ; Fri, 26 Oct 2007 14:41:28 -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 l9QKfRbT011290 for ; Fri, 26 Oct 2007 14:41:28 -0600 Received: from weaponx.rchland.ibm.com (weaponx.rchland.ibm.com [9.10.86.71]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id l9QKfRjq011248; Fri, 26 Oct 2007 14:41:27 -0600 Date: Fri, 26 Oct 2007 20:41:00 -0000 From: Josh Boyer To: benh@kernel.crashing.org Cc: Daniel Jacobowitz , gdb@sourceware.org, linuxppc-embedded@ozlabs.org, Matt Mackall Subject: Re: Apparent kernel bug with GDB on ppc405 Message-ID: <20071026154126.28082129@weaponx.rchland.ibm.com> In-Reply-To: <1193363482.7018.41.camel@pasglop> References: <20071024194640.GB19691@waste.org> <20071024204215.GC19691@waste.org> <20071024215421.GF19691@waste.org> <20071024223250.GI19691@waste.org> <20071024224130.GA30819@caradoc.them.org> <1193363482.7018.41.camel@pasglop> X-Mailer: Claws Mail 3.0.2 (GTK+ 2.10.14; powerpc-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2007-10/txt/msg00278.txt.bz2 On Fri, 26 Oct 2007 11:51:22 +1000 Benjamin Herrenschmidt wrote: > > On Wed, 2007-10-24 at 18:41 -0400, Daniel Jacobowitz wrote: > > On Wed, Oct 24, 2007 at 05:32:50PM -0500, Matt Mackall wrote: > > > Not completely implausible, but a) why isn't this seen on basically > > > every machine with software TLB? b) why does -local- GDB, which is > > > presumably doing much less work than gdbserver + network stack, not fail? > > > > You said it yourself. Local gdb does more work -> blows through more > > TLB entries. > > > > I can't answer you about the other half, but I'm pretty sure TLB > > invalidation is already supposed to be happening... somewhere. > > Yes. do_wp_page() -> ptep_clear_flush() -> flush_tlb_page() Aren't there cases in do_wp_page that don't call ptep_clear_flush? Seems anonymous pages, and possibly shared writeable pages skip that step if reuse is true. josh