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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81F65C28B2B for ; Thu, 18 Aug 2022 21:17:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346802AbiHRVRH (ORCPT ); Thu, 18 Aug 2022 17:17:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346630AbiHRVPR (ORCPT ); Thu, 18 Aug 2022 17:15:17 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB342DDA85 for ; Thu, 18 Aug 2022 14:07:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660856867; x=1692392867; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=GmkbBbjW1HbR2hnXSAPeOB4FglG3wvlQRjoDRd8WvxM=; b=mlBnhip74xFnZAhv/6vUi+kkNwlGqC1pN41C6i9sTUnprYMdIUvwaOs7 Nh3qR+838nhHs3GU+wEczQFHMNOQddU/Bo2BeA/CbfD9uovFnD5mvsnQs 4Y9ikQwG4Zg4mh0amIyjBbZzgOyKxaVNmf7bVJjxm/pKeUa3MAqZcOZ2A 457wHr/+V4KOe7A3tvAwd8YjuPfS+5e5P4MmIFnbgQcIntDCH0MiJenCk Nc2Z/k3Fmgqz1s3eZdprdoHMUW43QV4qd4GgBodM1zItTXJl95gKjeahh xg78ebxO82Y83YOITgpp5rzv4Q/9GzY/oj/qwQnDov1XBln9uPYInLUdF w==; X-IronPort-AV: E=McAfee;i="6500,9779,10443"; a="294147250" X-IronPort-AV: E=Sophos;i="5.93,247,1654585200"; d="scan'208";a="294147250" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2022 14:07:46 -0700 X-IronPort-AV: E=Sophos;i="5.93,247,1654585200"; d="scan'208";a="853552702" Received: from tathomp-mobl.amr.corp.intel.com (HELO [10.212.238.171]) ([10.212.238.171]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2022 14:07:46 -0700 Message-ID: <19144f97-2b00-fed6-5395-0221bbc60802@intel.com> Date: Thu, 18 Aug 2022 14:07:45 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH RFC] mm, proc: add PcpFree to meminfo Content-Language: en-US To: Kefeng Wang , Andrew Morton , Greg Kroah-Hartman , linux-mm@kvack.org, Aaron Lu , Michal Hocko , Jesper Dangaard Brouer , Vlastimil Babka , Kemi Wang Cc: linux-kernel@vger.kernel.org, Liu Shixin References: <20220816084426.135528-1-wangkefeng.wang@huawei.com> <99556483-9f22-4597-8270-b4414cc97e64@huawei.com> From: Dave Hansen In-Reply-To: <99556483-9f22-4597-8270-b4414cc97e64@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/17/22 00:16, Kefeng Wang wrote: > On 2022/8/16 16:44, Kefeng Wang wrote: >> From: Liu Shixin >> >> The page on pcplist could be used, but not counted into memory free or >> avaliable, and pcp_free is only showed by show_mem(). Since commit >> d8a759b57035 ("mm, page_alloc: double zone's batchsize"), there is a >> significant decrease in the display of free memory, with a large number >> of cpus and nodes, the number of pages in the percpu list can be very >> large, so it is better to let user to know the pcp count. > Add more experts according to commit d8a759b57035， > any advice would be much appreciated，thanks. Adding a new meminfo field seems like overkill. I'd just make this a part of MemFree if anything. Also, some actual data would be nice here. Like: Before commit d8a759b57035, the maximum amount of pages in the pcp lists was theoretically $FOO MB. After the patch, the lists can hold $BAR MB. It has been observed to be $BAZ MB in practice. This was all on a system with $X memory NUMA nodes and $Y CPUs.