Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932117AbVLLSZi (ORCPT ); Mon, 12 Dec 2005 13:25:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932118AbVLLSZi (ORCPT ); Mon, 12 Dec 2005 13:25:38 -0500 Received: from stat9.steeleye.com ([209.192.50.41]:33512 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S932117AbVLLSZh (ORCPT ); Mon, 12 Dec 2005 13:25:37 -0500 Subject: Re: Fw: crash on x86_64 - mm related? From: James Bottomley To: Linus Torvalds Cc: Ryan Richter , Hugh Dickins , Kai Makisara , Andrew Morton , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org In-Reply-To: References: <20051201195657.GB7236@tau.solarneutrino.net> <20051202180326.GB7634@tau.solarneutrino.net> <20051202194447.GA7679@tau.solarneutrino.net> <20051206160815.GC11560@tau.solarneutrino.net> <20051206204336.GA12248@tau.solarneutrino.net> <20051212165443.GD17295@tau.solarneutrino.net> <1134409531.9994.13.camel@mulgrave> Content-Type: text/plain Date: Mon, 12 Dec 2005 12:24:42 -0600 Message-Id: <1134411882.9994.18.camel@mulgrave> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1304 Lines: 32 On Mon, 2005-12-12 at 10:09 -0800, Linus Torvalds wrote: > Well, that patch is definitely broken. No, it's not; all it's doing is deferring the device_put() from the scsi_put_command() to after the scsi_run_queue(), which doesn't fix the sleep while atomic problem of the device release method. In both cases we still get the semaphore in atomic context problem which is caused by scsi_reap_target() doing a device_del(), which I assumed (wrongly) was valid from atomic context. I'll fix the scsi_reap_target(), but it's nothing to do with the patch you reversed. > You say that it just causes a warning about sleeping in interrupt context, > while I say that the warning is a serious error. If that semaphore _ever_ > is write-locked, the whole machine will crash from trying to sleep when it > cannot sleep. > > So I can certainly undo the undo, but the fact is, the code is CRAP. I'd > much rather get a real fix instead of having to select between two known > bugs. I'll find a fix for the real problem, but this patch isn't the cause. James - 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/