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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 224CBC433B4 for ; Wed, 14 Apr 2021 14:39:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D055560FF3 for ; Wed, 14 Apr 2021 14:39:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233830AbhDNOja (ORCPT ); Wed, 14 Apr 2021 10:39:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231678AbhDNOjZ (ORCPT ); Wed, 14 Apr 2021 10:39:25 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36ED2C061574 for ; Wed, 14 Apr 2021 07:39:03 -0700 (PDT) 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=0Sv9NEP22wjna5CIpFfxEXT3qRzPSodaVUOesDxk1QA=; b=VLkGN1vJjSHuydMty0NSFfPDnq avZRQ4ysQU5wSO8a8yVkJqe6H5ZsDqXUGlxnLpeH+8sLO8LBS7sdU6I64XNB8GUnn0HH3aJIQxZMd LvjncF+hpEmIgxElClojr6YNbkmIhgzlyUfUQ02+eOnW5G0zWLrFmmYms3I/yfVF4YsNJa8ZWcsu1 m7xA6Sq8ZeNzmQUxfYZexyEceaK9rqjr1VWRzYgfZxcv51N8LnLrWqP+HOSf+4VvxTdjwpj5ePMOw kXrXk6zE9M0TqHymq07CJGeaCU67MmcmQjpIvbSKFpr2C4KzHpGfh3rlYrKKnPXr8lfs1E1Odbm8b YKFKDqLA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lWgd0-007EGl-DK; Wed, 14 Apr 2021 14:36:29 +0000 Date: Wed, 14 Apr 2021 15:36:26 +0100 From: Matthew Wilcox To: Yu Zhao Cc: linux-mm@kvack.org, Alex Shi , Andi Kleen , Andrew Morton , Benjamin Manes , Dave Chinner , Dave Hansen , Hillf Danton , Jens Axboe , Johannes Weiner , Jonathan Corbet , Joonsoo Kim , Mel Gorman , Miaohe Lin , Michael Larabel , Michal Hocko , Michel Lespinasse , Rik van Riel , Roman Gushchin , Rong Chen , SeongJae Park , Tim Chen , Vlastimil Babka , Yang Shi , Ying Huang , Zi Yan , linux-kernel@vger.kernel.org, lkp@lists.01.org, page-reclaim@google.com Subject: Re: [PATCH v2 10/16] mm: multigenerational lru: mm_struct list Message-ID: <20210414143626.GT2531743@casper.infradead.org> References: <20210413065633.2782273-1-yuzhao@google.com> <20210413065633.2782273-11-yuzhao@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210413065633.2782273-11-yuzhao@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 13, 2021 at 12:56:27AM -0600, Yu Zhao wrote: > In order to scan page tables, we add an infrastructure to maintain > either a system-wide mm_struct list or per-memcg mm_struct lists. > Multiple threads can concurrently work on the same mm_struct list, and > each of them will be given a different mm_struct. > > This infrastructure also tracks whether an mm_struct is being used on > any CPUs or has been used since the last time a worker looked at it. > In other words, workers will not be given an mm_struct that belongs to > a process that has been sleeping. This seems like a great use for an allocating XArray. You can use a search mark to indicate whether it's been used since the last time a worker looked at it.