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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 686F1C433DF for ; Fri, 7 Aug 2020 19:35:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0490F204EC for ; Fri, 7 Aug 2020 19:35:21 +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="nEnfdelS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0490F204EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4F3748D0007; Fri, 7 Aug 2020 15:35:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 47AF68D0005; Fri, 7 Aug 2020 15:35:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 390668D0007; Fri, 7 Aug 2020 15:35:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0157.hostedemail.com [216.40.44.157]) by kanga.kvack.org (Postfix) with ESMTP id 23B268D0005 for ; Fri, 7 Aug 2020 15:35:21 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id BB202362C for ; Fri, 7 Aug 2020 19:35:20 +0000 (UTC) X-FDA: 77124776400.09.vase83_51158bf26fc2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 89E0D180AD802 for ; Fri, 7 Aug 2020 19:35:20 +0000 (UTC) X-HE-Tag: vase83_51158bf26fc2 X-Filterd-Recvd-Size: 3542 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 19:35:19 +0000 (UTC) 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=t2izdhy9urvECJgu7c0L+DP8+hLwhvJe9LrSJI1uUoU=; b=nEnfdelSe1G9Q+nx+YpNh0mw1/ +a4gGLD0aa9HwBzJxEjQA3qi4g3PXKSq79Y2zY7r0uTtXUyt2tr8itdma+mPNnJjLysKop3luLRvG +s7fjtFyK5BDV4QlN7hM/nOamL+SwvA0z5nuEEDEVkjWFjr9iEPhOAGmNcZDkABfyKoAlFsgnfKBI dcflAoOAEb0LQ5wMksJBIOfeRdBCdYEXiElhQbz8I5flB4ii8eeyt7t8c0xOeXGXxXRhYURPthiAf RSriqo9p5uWoZquYNMFKQWc4plLasbaF3PUqWR6M8S7fAD6PS3GH5YwF8HMfn+hn0rAXP3VhMVAj3 wjY/kmAg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k4890-0001tN-N2; Fri, 07 Aug 2020 19:35:10 +0000 Date: Fri, 7 Aug 2020 20:35:10 +0100 From: Matthew Wilcox To: Hugh Dickins Cc: Linus Torvalds , Oleg Nesterov , Michal Hocko , Linux-MM , LKML , Andrew Morton , Tim Chen , Michal Hocko , Greg KH Subject: Re: [RFC PATCH] mm: silence soft lockups from unlock_page Message-ID: <20200807193510.GG17456@casper.infradead.org> References: <20200725101445.GB3870@redhat.com> <20200806180024.GB17456@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 89E0D180AD802 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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, Aug 07, 2020 at 11:41:09AM -0700, Hugh Dickins wrote: > My home testing was, effectively, on top of c6fe44d96fc1 (v5.8 plus > your two patches): I did not have in the io_uring changes from the > current tree. In glancing there, I noticed one new and one previous > instance of SetPageWaiters() *after* __add_wait_queue_entry_tail(): > are those correct? By the way, don't do any performance testing on current Linus tree. This commit: commit 37f4a24c2469a10a4c16c641671bd766e276cf9f (refs/bisect/bad) Author: Ming Lei Date: Tue Jun 30 22:03:57 2020 +0800 blk-mq: centralise related handling into blk_mq_get_driver_tag Move .nr_active update and request assignment into blk_mq_get_driver_tag(), all are good to do during getting driver tag. Meantime blk-flush related code is simplified and flush request needn't to update the request table manually any more. Signed-off-by: Ming Lei Cc: Christoph Hellwig Signed-off-by: Jens Axboe slows everything down, at least on my test qemu system. Seems like it's losing block queue tags.