From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: About the try to remove cross-release feature entirely by Ingo To: Theodore Ts'o , Matthew Wilcox , Byungchul Park , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , david@fromorbit.com, Linus Torvalds , Amir Goldstein , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, oleg@redhat.com, kernel-team@lge.com, daniel@ffwll.ch References: <20171229014736.GA10341@X58A-UD3R> <20171229035146.GA11757@thunk.org> <20171229072851.GA12235@X58A-UD3R> <20171230061624.GA27959@bombadil.infradead.org> <20171230154041.GB3366@thunk.org> <20171230204417.GF27959@bombadil.infradead.org> <20171230224028.GC3366@thunk.org> From: Byungchul Park Message-ID: Date: Wed, 3 Jan 2018 11:10:37 +0900 MIME-Version: 1.0 In-Reply-To: <20171230224028.GC3366@thunk.org> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 12/31/2017 7:40 AM, Theodore Ts'o wrote: > On Sat, Dec 30, 2017 at 12:44:17PM -0800, Matthew Wilcox wrote: >> >> I'm not sure I agree with this part. What if we add a new TCP lock class >> for connections which are used for filesystems/network block devices/...? >> Yes, it'll be up to each user to set the lockdep classification correctly, >> but that's a relatively small number of places to add annotations, >> and I don't see why it wouldn't work. > > I was exagerrating a bit for effect, I admit. (but only a bit). > > It can probably be for all TCP connections that are used by kernel > code (as opposed to userspace-only TCP connections). But it would > probably have to be each and every device-mapper instance, each and > every block device, each and every mounted file system, each and every > bdi object, etc. > > The point I was trying to drive home is that "all we have to do is > just classify everything well or just invalidate the right lock Just to be sure, we don't have to invalidate lock objects at all but a problematic waiter only. > objects" is a massive understatement of the complexity level of what > would be required, or the number of locks/completion handlers that > would have to be blacklisted. > > - Ted > -- Thanks, Byungchul From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: About the try to remove cross-release feature entirely by Ingo To: Theodore Ts'o , Matthew Wilcox , Byungchul Park , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , david@fromorbit.com, Linus Torvalds , Amir Goldstein , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, oleg@redhat.com, kernel-team@lge.com, daniel@ffwll.ch References: <20171229014736.GA10341@X58A-UD3R> <20171229035146.GA11757@thunk.org> <20171229072851.GA12235@X58A-UD3R> <20171230061624.GA27959@bombadil.infradead.org> <20171230154041.GB3366@thunk.org> <20171230204417.GF27959@bombadil.infradead.org> <20171230224028.GC3366@thunk.org> From: Byungchul Park Message-ID: Date: Wed, 3 Jan 2018 11:10:37 +0900 MIME-Version: 1.0 In-Reply-To: <20171230224028.GC3366@thunk.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: On 12/31/2017 7:40 AM, Theodore Ts'o wrote: > On Sat, Dec 30, 2017 at 12:44:17PM -0800, Matthew Wilcox wrote: >> >> I'm not sure I agree with this part. What if we add a new TCP lock class >> for connections which are used for filesystems/network block devices/...? >> Yes, it'll be up to each user to set the lockdep classification correctly, >> but that's a relatively small number of places to add annotations, >> and I don't see why it wouldn't work. > > I was exagerrating a bit for effect, I admit. (but only a bit). > > It can probably be for all TCP connections that are used by kernel > code (as opposed to userspace-only TCP connections). But it would > probably have to be each and every device-mapper instance, each and > every block device, each and every mounted file system, each and every > bdi object, etc. > > The point I was trying to drive home is that "all we have to do is > just classify everything well or just invalidate the right lock Just to be sure, we don't have to invalidate lock objects at all but a problematic waiter only. > objects" is a massive understatement of the complexity level of what > would be required, or the number of locks/completion handlers that > would have to be blacklisted. > > - Ted > -- Thanks, Byungchul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org