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=-3.8 required=3.0 tests=BAYES_00, 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 EDFB0C433B4 for ; Sat, 24 Apr 2021 03:30:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D18F06146B for ; Sat, 24 Apr 2021 03:30:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236914AbhDXDbX (ORCPT ); Fri, 23 Apr 2021 23:31:23 -0400 Received: from mga06.intel.com ([134.134.136.31]:48382 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232155AbhDXDbR (ORCPT ); Fri, 23 Apr 2021 23:31:17 -0400 IronPort-SDR: C3O9MesraxACpLR34qZmPN1I/AxS8edirfalVLsPM9eyFG44E3zR42J7g4dNK3RFbigttUh97C xwp7koxh0a0Q== X-IronPort-AV: E=McAfee;i="6200,9189,9963"; a="257463733" X-IronPort-AV: E=Sophos;i="5.82,247,1613462400"; d="scan'208";a="257463733" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Apr 2021 20:30:40 -0700 IronPort-SDR: GDpt/XE7DF3GrhacVF7Vpy23laFs/roeoUFy5BkMWagdXnUZPnMTIHXrOT2kg1nyQPmPbyfdlb ehwP5e+VqEkQ== X-IronPort-AV: E=Sophos;i="5.82,247,1613462400"; d="scan'208";a="535711869" Received: from tassilo.jf.intel.com ([10.54.74.11]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Apr 2021 20:30:40 -0700 Date: Fri, 23 Apr 2021 20:30:38 -0700 From: Andi Kleen To: Yu Zhao Cc: Michel Lespinasse , Rik van Riel , Ying Huang , Dave Chinner , Jens Axboe , SeongJae Park , Linux-MM , Andrew Morton , Benjamin Manes , Dave Hansen , Hillf Danton , Johannes Weiner , Jonathan Corbet , Joonsoo Kim , Matthew Wilcox , Mel Gorman , Miaohe Lin , Michael Larabel , Michal Hocko , Roman Gushchin , Rong Chen , SeongJae Park , Tim Chen , Vlastimil Babka , Yang Shi , Zi Yan , linux-kernel , lkp@lists.01.org, Kernel Page Reclaim v2 Subject: Re: [PATCH v2 00/16] Multigenerational LRU Framework Message-ID: <20210424033038.GP1401198@tassilo.jf.intel.com> References: <3ddd4f8a-8e51-662b-df11-a63a0e75b2bc@kernel.dk> <20210413231436.GF63242@dread.disaster.area> <20210414155130.GU3762101@tassilo.jf.intel.com> <20210415030002.GX3762101@tassilo.jf.intel.com> <20210415095708.GA6874@lespinasse.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Now the question is how we build the bloom filter. A simple answer is > to let the rmap do the legwork, i.e., when it encounters dense > regions, add them to the filter. Of course this means we'll have to > use the rmap more than we do now, which is not ideal for some > workloads but necessary to avoid worst case scenarios. How would you maintain the bloom filter over time? Assume a process that always creates new mappings and unmaps old mappings. How do the stale old mappings get removed and avoid polluting it over time? Or are you thinking of one of the fancier bloom filter variants that support deletion? As I understand they're significantly less space efficient and more complicated. -Andi