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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 609DCC433EF for ; Wed, 24 Nov 2021 15:58:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CC8E16B007E; Wed, 24 Nov 2021 10:58:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C76DB6B0080; Wed, 24 Nov 2021 10:58:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B663A6B0081; Wed, 24 Nov 2021 10:58:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0106.hostedemail.com [216.40.44.106]) by kanga.kvack.org (Postfix) with ESMTP id 0D1A16B007E for ; Wed, 24 Nov 2021 10:58:15 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id C48238D8CE for ; Wed, 24 Nov 2021 15:58:04 +0000 (UTC) X-FDA: 78844280046.07.FD73427 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf07.hostedemail.com (Postfix) with ESMTP id 6C3DA10002CB for ; Wed, 24 Nov 2021 15:58:00 +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=MhRaQX30y19nymtN7XiLLZlWbPS4SbobGvSOfL7Qrks=; b=VWcQqruxbm2TEfSiEDvRf8EWp9 i4YG+LkmraO3TfeifQvSRMDp6DVtjo6NuwHNNm7w9mmMhrdT3SoBe/tWe9brqTvQCZ7jZUs6T0ucc vX+aljEB/gNCEfxEjmrvv1+l395R0ThnB3iMrTAWrRMm3oTJnw94MzsSCTYF9QVeUI0p6A/2fLGBO 61/8h4OIX0YlAYL8ybhL7MGaTNJuJM7ANRwGzp6TSshTFLDK40NOPz8IxvN54L3X/2lH89qqxL/rZ 30wTPCtMr9Af5wOwli4O35Aca/Kgj0bE4wh2bXS9hHoU4/Dprs+kxcoVXS5U3v6/S6uE50Fiff0EE TAzAkjEA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mpuek-002Pnu-QR; Wed, 24 Nov 2021 15:57:58 +0000 Date: Wed, 24 Nov 2021 15:57:58 +0000 From: Matthew Wilcox To: Hao Lee Cc: linux-mm@kvack.org, hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, shakeelb@google.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: reduce spinlock contention in release_pages() Message-ID: References: <20211124151915.GA6163@haolee.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211124151915.GA6163@haolee.io> X-Rspamd-Queue-Id: 6C3DA10002CB X-Stat-Signature: rseoa7fed51xdrmsbkgtc1jpt1uubqy5 Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=VWcQqrux; dmarc=none; spf=none (imf07.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Rspamd-Server: rspam02 X-HE-Tag: 1637769480-231428 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 Wed, Nov 24, 2021 at 03:19:15PM +0000, Hao Lee wrote: > When several tasks are terminated simultaneously, lots of pages will be > released, which can cause severe spinlock contention. Other tasks which > are running on the same core will be seriously affected. We can yield > cpu to fix this problem. The realtime people will eat you alive for this suggestion. > +++ b/mm/swap.c > @@ -960,8 +960,14 @@ void release_pages(struct page **pages, int nr) > if (PageLRU(page)) { > struct lruvec *prev_lruvec = lruvec; > > - lruvec = folio_lruvec_relock_irqsave(folio, lruvec, > +retry: > + lruvec = folio_lruvec_tryrelock_irqsave(folio, lruvec, > &flags); > + if (!lruvec) { > + cond_resched(); > + goto retry; > + } > + > if (prev_lruvec != lruvec)