From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb0-f200.google.com (mail-yb0-f200.google.com [209.85.213.200]) by kanga.kvack.org (Postfix) with ESMTP id 1EA146B0038 for ; Sat, 30 Dec 2017 17:40:37 -0500 (EST) Received: by mail-yb0-f200.google.com with SMTP id a17so108750ybl.0 for ; Sat, 30 Dec 2017 14:40:37 -0800 (PST) Received: from imap.thunk.org (imap.thunk.org. [2600:3c02::f03c:91ff:fe96:be03]) by mx.google.com with ESMTPS id g130si7728496ywh.14.2017.12.30.14.40.35 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 30 Dec 2017 14:40:36 -0800 (PST) Date: Sat, 30 Dec 2017 17:40:28 -0500 From: Theodore Ts'o Subject: Re: About the try to remove cross-release feature entirely by Ingo Message-ID: <20171230224028.GC3366@thunk.org> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171230204417.GF27959@bombadil.infradead.org> Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: Byungchul Park , 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 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 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 -- 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