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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 389CBC433EF for ; Fri, 22 Oct 2021 13:17:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BF2D16112F for ; Fri, 22 Oct 2021 13:17:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org BF2D16112F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 0C30A900003; Fri, 22 Oct 2021 09:17:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0729B900002; Fri, 22 Oct 2021 09:17:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA2D4900003; Fri, 22 Oct 2021 09:17:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id DA8E4900002 for ; Fri, 22 Oct 2021 09:17:36 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 864E882499A8 for ; Fri, 22 Oct 2021 13:17:36 +0000 (UTC) X-FDA: 78724125312.03.A61C4B6 Received: from outbound-smtp30.blacknight.com (outbound-smtp30.blacknight.com [81.17.249.61]) by imf25.hostedemail.com (Postfix) with ESMTP id E9926B00018A for ; Fri, 22 Oct 2021 13:17:30 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp30.blacknight.com (Postfix) with ESMTPS id 4321018093 for ; Fri, 22 Oct 2021 14:17:34 +0100 (IST) Received: (qmail 6329 invoked from network); 22 Oct 2021 13:17:34 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 22 Oct 2021 13:17:34 -0000 Date: Fri, 22 Oct 2021 14:17:32 +0100 From: Mel Gorman To: NeilBrown Cc: Andrew Morton , Theodore Ts'o , Andreas Dilger , "Darrick J . Wong" , Matthew Wilcox , Michal Hocko , Dave Chinner , Rik van Riel , Vlastimil Babka , Johannes Weiner , Jonathan Corbet , Linux-MM , Linux-fsdevel , LKML Subject: Re: [PATCH v4 0/8] Remove dependency on congestion_wait in mm/ Message-ID: <20211022131732.GK3959@techsingularity.net> References: <20211019090108.25501-1-mgorman@techsingularity.net> <163486531001.17149.13533181049212473096@noble.neil.brown.name> <20211022083927.GI3959@techsingularity.net> <163490199006.17149.17259708448207042563@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <163490199006.17149.17259708448207042563@noble.neil.brown.name> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: E9926B00018A Authentication-Results: imf25.hostedemail.com; dkim=none; spf=pass (imf25.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.61 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net; dmarc=none X-Stat-Signature: qk4tafq9uat1nge4r1sk4or1uakydzde X-Rspamd-Server: rspam06 X-HE-Tag: 1634908650-440130 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 22, 2021 at 10:26:30PM +1100, NeilBrown wrote: > On Fri, 22 Oct 2021, Mel Gorman wrote: > > On Fri, Oct 22, 2021 at 12:15:10PM +1100, NeilBrown wrote: > > > > > In general, I still don't like the use of wake_up_all(), though it won't > > > cause incorrect behaviour. > > > > > > > Removing wake_up_all would be tricky. > > I think there is a misunderstanding. Removing wake_up_all() is as > simple as > s/wake_up_all/wake_up/ > > If you used prepare_to_wait_exclusive(), then wake_up() would only wake > one waiter, while wake_up_all() would wake all of them. > As you use prepare_to_wait(), wake_up() will wake all waiters - as will > wake_up_all(). > Ok, yes, there was a misunderstanding. I thought you were suggesting a move to exclusive wakeups. I felt that the wake_up_all was explicit in terms of intent and that I really meant for all tasks to wake instead of one at a time. -- Mel Gorman SUSE Labs