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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2286AC47404 for ; Fri, 11 Oct 2019 23:20:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DDEBA2089F for ; Fri, 11 Oct 2019 23:20:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDEBA2089F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 89CB06B0003; Fri, 11 Oct 2019 19:20:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 84DE78E0005; Fri, 11 Oct 2019 19:20:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7623E8E0001; Fri, 11 Oct 2019 19:20:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0025.hostedemail.com [216.40.44.25]) by kanga.kvack.org (Postfix) with ESMTP id 4FFC16B0003 for ; Fri, 11 Oct 2019 19:20:37 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id EC4CA6D81 for ; Fri, 11 Oct 2019 23:20:36 +0000 (UTC) X-FDA: 76033075272.07.twig45_5509dabe8f43 X-HE-Tag: twig45_5509dabe8f43 X-Filterd-Recvd-Size: 2463 Received: from mail105.syd.optusnet.com.au (mail105.syd.optusnet.com.au [211.29.132.249]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Fri, 11 Oct 2019 23:20:36 +0000 (UTC) Received: from dread.disaster.area (pa49-181-198-88.pa.nsw.optusnet.com.au [49.181.198.88]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id 1835C36268A; Sat, 12 Oct 2019 10:20:33 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.2) (envelope-from ) id 1iJ4D3-0007jx-0D; Sat, 12 Oct 2019 10:20:33 +1100 Date: Sat, 12 Oct 2019 10:20:32 +1100 From: Dave Chinner To: Matthew Wilcox Cc: linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Jens Axboe Subject: Re: [PATCH 14/26] mm: back off direct reclaim on excessive shrinker deferral Message-ID: <20191011232032.GN16973@dread.disaster.area> References: <20191009032124.10541-1-david@fromorbit.com> <20191009032124.10541-15-david@fromorbit.com> <20191011162105.GU32665@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191011162105.GU32665@bombadil.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.2 cv=D+Q3ErZj c=1 sm=1 tr=0 a=ocld+OpnWJCUTqzFQA3oTA==:117 a=ocld+OpnWJCUTqzFQA3oTA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=XobE76Q3jBoA:10 a=7-415B0cAAAA:8 a=JuDxSlhT3OO6blO4plAA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Oct 11, 2019 at 09:21:05AM -0700, Matthew Wilcox wrote: > On Wed, Oct 09, 2019 at 02:21:12PM +1100, Dave Chinner wrote: > > + if ((reclaim_state->deferred_objects > > > + sc->nr_scanned - nr_scanned) && > > + (reclaim_state->deferred_objects > > > + reclaim_state->scanned_objects)) { > > + wait_iff_congested(BLK_RW_ASYNC, HZ/50); > > Unfortunately, Jens broke wait_iff_congested() recently, and doesn't plan > to fix it. We need to come up with another way to estimate congestion. I know, all the ways the block layer is broken are right there in the cover letter at the end of the v1 patchset description from more than 2 months ago. When people work out how to fix congestion detection and backoff again, this can be updated at the same time. Cheers, Dave. -- Dave Chinner david@fromorbit.com