From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4EDDC433DF for ; Wed, 1 Jul 2020 18:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B45A6207F5 for ; Wed, 1 Jul 2020 18:25:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="o7SDqMAw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732990AbgGASZm (ORCPT ); Wed, 1 Jul 2020 14:25:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732835AbgGASZm (ORCPT ); Wed, 1 Jul 2020 14:25:42 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29356C08C5C1; Wed, 1 Jul 2020 11:25:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=79iDJfFRYlYHrisn3ouDHG53Aq0lK8z2VddrdPxeVyA=; b=o7SDqMAwBo7t+TzTt83Wnbb4Mf /u3FPb35bitwFjn51sx/gj3Y9SatyNLQ4rgWXHyeRpDSuy2msqXigA7OPbbMBLBZH4hqJdMl6nn4j o+oNlcrRUlnxx6s1auiuL4a9abVDq46ghr0Ywah7Ao7UudMSVkL0IvmrZuixAAq9t7XLxby/vTDpD 66p1DhcwBNMn2HW7Kd0s1SbNOfzFt7MnNzqs6ZeP2YjAYbVADLriPSyKR43Cxp2dGBQbRz1ID7kyG wnhB7OkOwvB4o3qDO8VvcqOP5sGj6DpgyZfHicwM2Rmsyv+O6qL0Q2QA193Apy1eQwBhl+yj/wnuE eK83FPaA==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jqhQQ-0004j0-GK; Wed, 01 Jul 2020 18:25:38 +0000 Date: Wed, 1 Jul 2020 19:25:38 +0100 From: Matthew Wilcox To: Mike Snitzer Cc: Christoph Hellwig , Jens Axboe , linux-raid@vger.kernel.org, linux-mm@kvack.org, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, drbd-dev@tron.linbit.com, dm-devel@redhat.com, Tejun Heo , cgroups@vger.kernel.org, linux-btrfs@vger.kernel.org Subject: Re: remove dead bdi congestion leftovers Message-ID: <20200701182538.GU25523@casper.infradead.org> References: <20200701090622.3354860-1-hch@lst.de> <20200701164103.GC27063@redhat.com> <20200701175747.GT25523@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200701175747.GT25523@casper.infradead.org> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Jul 01, 2020 at 06:57:47PM +0100, Matthew Wilcox wrote: > On Wed, Jul 01, 2020 at 12:41:03PM -0400, Mike Snitzer wrote: > > On Wed, Jul 01 2020 at 5:06am -0400, > > Christoph Hellwig wrote: > > > > > Hi Jens, > > > > > > we have a lot of bdi congestion related code that is left around without > > > any use. This series removes it in preparation of sorting out the bdi > > > lifetime rules properly. > > > > I could do some git archeology to see what the fs, mm and block core > > changes were to stop using bdi congested but a pointer to associated > > changes (or quick recap) would save me some time. > > > > Also, curious to know how back-pressure should be felt back up the IO > > stack now? (apologies if these are well worn topics, I haven't been > > tracking this area of development). > > It isn't. Jens declared the implementation was broken, and broke it > more. So we're just living with stupid broken timeouts. Here's a thread about it. This would have been a discussion topic at LSFMM2020, but COVID. https://lore.kernel.org/linux-mm/20190917115824.16990-1-linf@wangsu.com/T/#u