[{"id":1762320,"web_url":"http://patchwork.ozlabs.org/comment/1762320/","msgid":"<20170903.110120.230269539906979454.davem@davemloft.net>","list_archive_url":null,"date":"2017-09-03T18:01:20","subject":"Re: [PATCH net 0/2] net: revert lib/percpu_counter API for\n\tfragmentation mem accounting","submitter":{"id":15,"url":"http://patchwork.ozlabs.org/api/people/15/","name":"David Miller","email":"davem@davemloft.net"},"content":"From: Jesper Dangaard Brouer \nDate: Fri, 01 Sep 2017 11:26:03 +0200\n\n> There is a bug in fragmentation codes use of the percpu_counter API,\n> that can cause issues on systems with many CPUs, above 24 CPUs.\n> \n> After much consideration and different attempts at solving the API\n> usage. The conclusion is to revert to the simple atomic_t API instead.\n> \n> The ratio between batch size and threshold size make it a bad use-case\n> for the lib/percpu_counter API. As using the correct API calls will\n> unfortunately cause systems with many CPUs to always execute an\n> expensive sum across all CPUs. Plus the added complexity is not worth it.\n\nSeries applied, thanks Jesper.","headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xlglS5wNRz9t3f\n\tfor ;\n\tMon, 4 Sep 2017 04:01:24 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1753156AbdICSBW (ORCPT );\n\tSun, 3 Sep 2017 14:01:22 -0400","from shards.monkeyblade.net ([184.105.139.130]:56454 \"EHLO\n\tshards.monkeyblade.net\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1753099AbdICSBV (ORCPT\n\t); Sun, 3 Sep 2017 14:01:21 -0400","from localhost (74-93-104-98-Washington.hfc.comcastbusiness.net\n\t[74.93.104.98]) (using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(Client did not present a certificate)\n\t(Authenticated sender: davem-davemloft)\n\tby shards.monkeyblade.net (Postfix) with ESMTPSA id 5C4BA120FBE82;\n\tSun, 3 Sep 2017 11:01:21 -0700 (PDT)"],"Date":"Sun, 03 Sep 2017 11:01:20 -0700 (PDT)","Message-Id":"<20170903.110120.230269539906979454.davem@davemloft.net>","To":"brouer@redhat.com","Cc":"netdev@vger.kernel.org, mkubecek@suse.cz, fw@strlen.de,\n\tliujian56@huawei.com","Subject":"Re: [PATCH net 0/2] net: revert lib/percpu_counter API for\n\tfragmentation mem accounting","From":"David Miller ","In-Reply-To":"<150425790711.22227.12264977619066874632.stgit@firesoul>","References":"<150425790711.22227.12264977619066874632.stgit@firesoul>","X-Mailer":"Mew version 6.7 on Emacs 25.2 / Mule 6.0 (HANACHIRUSATO)","Mime-Version":"1.0","Content-Type":"Text/Plain; charset=us-ascii","Content-Transfer-Encoding":"7bit","X-Greylist":"Sender succeeded SMTP AUTH, not delayed by\n\tmilter-greylist-4.5.12 (shards.monkeyblade.net\n\t[149.20.54.216]); Sun, 03 Sep 2017 11:01:21 -0700 (PDT)","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"}}]