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 8FBD6C28B2B for ; Fri, 19 Aug 2022 01:06:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243365AbiHSBGw (ORCPT ); Thu, 18 Aug 2022 21:06:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230359AbiHSBGu (ORCPT ); Thu, 18 Aug 2022 21:06:50 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7370AB729E for ; Thu, 18 Aug 2022 18:06:48 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.53]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4M83Qz4BF2z1N7RY; Fri, 19 Aug 2022 09:03:23 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 19 Aug 2022 09:06:46 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 19 Aug 2022 09:06:45 +0800 Message-ID: Date: Fri, 19 Aug 2022 09:06:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH RFC] mm, proc: add PcpFree to meminfo Content-Language: en-US To: Dave Hansen , Andrew Morton , Greg Kroah-Hartman , , Aaron Lu , Michal Hocko , Jesper Dangaard Brouer , "Vlastimil Babka" , Kemi Wang CC: , Liu Shixin References: <20220816084426.135528-1-wangkefeng.wang@huawei.com> <99556483-9f22-4597-8270-b4414cc97e64@huawei.com> <19144f97-2b00-fed6-5395-0221bbc60802@intel.com> From: Kefeng Wang In-Reply-To: <19144f97-2b00-fed6-5395-0221bbc60802@intel.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/8/19 5:07, Dave Hansen wrote: > 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. I like this way too. > 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. > > . Same question in [1],  will repost with update, thanks. [1] https://lore.kernel.org/linux-mm/03f465ca-cf8e-bbd1-1083-099fd2ce026d@huawei.com/t/#m50cf15911d9d203bd97238512fa2ae9ba1bd9e1e