Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 9 Jul 2002 17:43:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 9 Jul 2002 17:43:15 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.101]:47807 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id ; Tue, 9 Jul 2002 17:43:14 -0400 Message-ID: <3D2AF6EA.1030008@us.ibm.com> Date: Tue, 09 Jul 2002 07:44:58 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020607 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Robert Love CC: William Lee Irwin III , Rick Lindsley , Greg KH , kernel-janitor-discuss , linux-kernel@vger.kernel.org Subject: Re: BKL removal References: <20020709201703.GC27999@kroah.com> <200207092055.g69Ktt418608@eng4.beaverton .ibm.com> <20020709210053.GF25360@holomorphy.com> <1026249175.1033.1178.camel@sinai> <3D2AF10A.1020603@us.ibm.com> <1026250151.1623.1185.camel@sinai> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1624 Lines: 38 Robert Love wrote: > On Tue, 2002-07-09 at 07:19, Dave Hansen wrote: > >>Robert Love wrote: >> >>>The problem is, it is needed in a _lot_ of places. Mostly instances >>>where the lock is held across something that may implicitly sleep. >> >>And _that_ is why I wrote the BKL debugging patch, to help find these >>places at runtime. It may not be pretty, but it works. I'll post it >>again if you're interested. > > I saw the patch... the problem is we cannot say "oh I ran this code path > with the patch and did not see anything, it is safe". Can sleep != will > sleep, and thus we have code that 99% will not sleep but it may. That's a good point, but we have to start somewhere. I think this is a reasonable way to start looking for bad behavior. Since you have to fix all of them anyway, why not let the easy bunch come to you instead of seeking them out? In a couple of kernel versions, I'd like to make it a BUG() to use the BKL in a nested fashion, or hold it during a schedule. I think that his would be a reasonable thing to do during the early days of the first development series after we think we have this thing licked. But, that is admittedly ages from now in kernel time. The Stanford Checker or something resembling it would be invaluable here. It would be a hell of a lot better than my litle patch! -- Dave Hansen haveblue@us.ibm.com - 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/