Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964880AbWARII1 (ORCPT ); Wed, 18 Jan 2006 03:08:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964772AbWARII1 (ORCPT ); Wed, 18 Jan 2006 03:08:27 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:13547 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S964880AbWARII0 (ORCPT ); Wed, 18 Jan 2006 03:08:26 -0500 Date: Wed, 18 Jan 2006 09:08:28 +0100 From: Ingo Molnar To: Andrew Morton Cc: Nathan Lynch , anton@au1.ibm.com, linux-kernel@vger.kernel.org, michael@ellerman.id.au, linuxppc64-dev@ozlabs.org, serue@us.ibm.com, paulus@au1.ibm.com, Linus Torvalds Subject: Re: 2.6.15-mm4 failure on power5 Message-ID: <20060118080828.GA2324@elte.hu> References: <20060116063530.GB23399@sergelap.austin.ibm.com> <200601180032.46867.michael@ellerman.id.au> <20060117140050.GA13188@elte.hu> <200601181119.39872.michael@ellerman.id.au> <20060118033239.GA621@cs.umn.edu> <20060118063732.GA21003@elte.hu> <20060117225304.4b6dd045.akpm@osdl.org> <20060118072815.GR2846@localhost.localdomain> <20060117233734.506c2f2e.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060117233734.506c2f2e.akpm@osdl.org> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1105 Lines: 26 * Andrew Morton wrote: > > Yes, which would be why this code never triggered a warning when > > cpucontrol was a semaphore. > > Yup. Perhaps a sane fix which preserves the unpleasant semantics is > to do irqsave in the mutex debug code. i'd much rather remove that ugly hack from __might_sleep(). How many other bugs does it hide? Does it hide bugs that dont normally trigger during bootups on real hardware, but which could trigger on e.g. UML or on Xen? I really think such ugly workarounds are not justified, if other arches can get their act together. Would you make such an exception for other arches too, like ARM? an irqsave in the mutex debug code will uglify the kernel/mutex.c code - i'd have to add extra "unsigned long flags" lines. [It will also slow down the debug code a bit - an extra PUSHF has to be done.] Ingo - 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/