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 E8F36C433EF for ; Thu, 20 Jan 2022 10:43:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4E2766B00A4; Thu, 20 Jan 2022 05:43:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 491AE6B00A6; Thu, 20 Jan 2022 05:43:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 380736B00A8; Thu, 20 Jan 2022 05:43:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 2940C6B00A4 for ; Thu, 20 Jan 2022 05:43:05 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D51278249980 for ; Thu, 20 Jan 2022 10:43:04 +0000 (UTC) X-FDA: 79050327888.15.40A880F Received: from mail-lf1-f47.google.com (mail-lf1-f47.google.com [209.85.167.47]) by imf22.hostedemail.com (Postfix) with ESMTP id 7C526C0002 for ; Thu, 20 Jan 2022 10:43:04 +0000 (UTC) Received: by mail-lf1-f47.google.com with SMTP id o12so19848019lfu.12 for ; Thu, 20 Jan 2022 02:43:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=+8enaquFPBu9Rpl1lG/EB/zWJM1rWqPYYB01U+8SlZc=; b=oXvULXpXY39sn/jk9FL0LtiC63NW6iWNXXZVo5rqmBPF5xoqFHjU8jlcEnuXKQEI7Q Mx5lL1NbP0vXAfuawEE92Zi+fkjnoP+iz2gZQShMiGJmzFqk9E/dN+CKuPQiijbNSAa9 vDgaZ0UGpq3xYX0N2W37llQ9s4ktRUrU4UfuTK+arb82xBrlAVruWLXJTvBgCSqbzXbx /cfeFgRNZ+dh9Tnz3fq1kglShta/8PluJrqt1gyluxPloElSAJcOf8/ouQM7LTjgo4n5 CZWBPFtgmNooZ6qycOa8RmAH9o13sNJhcEmm1v3dCNNC1mU8ZvSCt3Bu0TEjzhmMlFv9 ziHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=+8enaquFPBu9Rpl1lG/EB/zWJM1rWqPYYB01U+8SlZc=; b=oLj7V+gplAQwiXSTZ00hvQSbC2wygbD6wSSC+e+S/F9SmOuXSZ23o7brq997k5l92c RcwezNWwZX5n/4gbxJH4BvlbM38WMktDg+RFdQ6kQi+dTPNgRwkzCxC8cBYrCA2MWwzV lpaMn7aazWfhsmut6lnBLFa7xR6JnDzgeB14W/NQm0Zfh/5Kj/BmDuywCbsGAm1BF4VO zn1P744IzmIL0uBk0txTwxZsBZwoi8ONBK49aufSKlrEwIH7WoPh/fCmiK5tYpCLzKH8 MsKuHYMH8ps5mRLlKhkPgx1M9YMwtOoRS9kk0lI4ORw8k3DolUM+XZX1HoZCI42Hivjb 8t3Q== X-Gm-Message-State: AOAM531aM9bYQROIMXl7TB5nqOxdMkh0X+8MbXntmqxcjv9fLG/EzMZX Sj8iyAavIIidcLsyx5UsECM= X-Google-Smtp-Source: ABdhPJxs3QH4HwQUqKal4LjMvk7mDm2E1Z0ozXp3fEq5x26kAJj6tCxvI44ITmPVr+BvCAWXOcgHZQ== X-Received: by 2002:a2e:9845:: with SMTP id e5mr24030748ljj.154.1642675382981; Thu, 20 Jan 2022 02:43:02 -0800 (PST) Received: from pc638.lan ([155.137.26.201]) by smtp.gmail.com with ESMTPSA id b7sm248930ljp.35.2022.01.20.02.42.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Jan 2022 02:43:01 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Thu, 20 Jan 2022 11:42:56 +0100 To: Christoph Hellwig Cc: "Uladzislau Rezki (Sony)" , Andrew Morton , linux-mm@kvack.org, LKML , Matthew Wilcox , Nicholas Piggin , Oleksiy Avramchenko Subject: Re: [PATCH 1/3] mm/vmalloc: Move draining areas out of caller context Message-ID: References: <20220119143540.601149-1-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 7C526C0002 X-Stat-Signature: dz8fih9t5b7zm6y1qajn3scsg9xagtk7 Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=oXvULXpX; spf=pass (imf22.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.47 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1642675384-302432 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, Jan 19, 2022 at 03:35:38PM +0100, Uladzislau Rezki (Sony) wrote: > > +static void drain_vmap_area(struct work_struct *work) > > Nit, but I prefer to have a _work postix for workers just to keep > it easy to ready. > Will fix it! > > /* After this point, we may free va at any time */ > > if (unlikely(nr_lazy > lazy_max_pages())) > > - try_purge_vmap_area_lazy(); > > + if (!atomic_xchg(&drain_vmap_area_work_in_progress, 1)) > > + schedule_work(&drain_vmap_area_work); > > Work items are defined to be single threaded, so I don't think we need > the drain_vmap_area_work_in_progress hack. > The motivation with that hack was to prevent the drain work being placed several times at once, i.e. schedule_work() checks only a pending bit. If the work is in run-queue another caller of vfree() will place it one more time, since pending bit is not set because the work is in TASK_RUNNING state. Or am i missing something? -- Vlad Rezki