From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756647AbYIRVUT (ORCPT ); Thu, 18 Sep 2008 17:20:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754236AbYIRVUH (ORCPT ); Thu, 18 Sep 2008 17:20:07 -0400 Received: from waste.org ([66.93.16.53]:35592 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752714AbYIRVUG (ORCPT ); Thu, 18 Sep 2008 17:20:06 -0400 Subject: Re: [patch] mm: tiny-shmem fix lor, mmap_sem vs i_mutex From: Matt Mackall To: Jeremy Fitzhardinge Cc: Ingo Molnar , Andrew Morton , Nick Piggin , a.p.zijlstra@chello.nl, linux-kernel@vger.kernel.org, Hugh Dickins , Dave Hansen In-Reply-To: <48D2ABFD.3040103@goop.org> References: <20080910121217.GA16013@elte.hu> <20080910144812.GB18644@wotan.suse.de> <1221058864.30429.291.camel@twins.programming.kicks-ass.net> <20080910152651.GE18644@wotan.suse.de> <20080911082709.GA14378@elte.hu> <20080914073906.GA6184@elte.hu> <20080914004442.4f8e851f.akpm@linux-foundation.org> <20080914080631.GA10720@elte.hu> <20080914221231.GG27080@wotan.suse.de> <20080917131419.e6b7622e.akpm@linux-foundation.org> <20080918111226.GD29968@elte.hu> <48D2ABFD.3040103@goop.org> Content-Type: text/plain Date: Thu, 18 Sep 2008 14:11:50 -0700 Message-Id: <1221772310.4779.29.camel@calx> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2008-09-18 at 12:29 -0700, Jeremy Fitzhardinge wrote: > Ingo Molnar wrote: > > in 7 days that's about 7000 random bootups, 20% of which had TINY_SHMEM > > enabled, half 32-bit, half 64-bit x86. It did not blow up in any way > > that would have prevented the kernel from building its next random > > version from within itself and it did not produce any kernel messages > > with various random kernel debug, compile and boot options. > > > > Does anything in that workload actually use shared memory? [adding Dave] For the record, Hugh tracked down the history of this bug and it went something like this: - I forked shmem.c and trimmed it down, keeping the function in question intact - Dave Hansen made divergent changes to shmem and tiny-shmem for reasons that aren't immediately obvious - Al Viro fixed a resultant dput bug - Nick fixed a resultant deadlock bug by undoing the divergence As far as Hugh and I can see, there was no reason for the divergent change. Really, we should probably re-unify the files to prevent such further confusion. -- Mathematics is the supreme nostalgia of our time.