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=-7.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 04B73C433DB for ; Fri, 5 Feb 2021 06:41:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A479B64F41 for ; Fri, 5 Feb 2021 06:41:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230513AbhBEGl5 (ORCPT ); Fri, 5 Feb 2021 01:41:57 -0500 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:3075 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230090AbhBEGlz (ORCPT ); Fri, 5 Feb 2021 01:41:55 -0500 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Thu, 04 Feb 2021 22:41:15 -0800 Received: from [10.2.60.31] (172.20.145.6) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 5 Feb 2021 06:41:15 +0000 Subject: Re: [PATCH] mm: cma: support sysfs To: Minchan Kim CC: Andrew Morton , , , , LKML , linux-mm References: <20210203155001.4121868-1-minchan@kernel.org> <7e7c01a7-27fe-00a3-f67f-8bcf9ef3eae9@nvidia.com> <87d7ec1f-d892-0491-a2de-3d0feecca647@nvidia.com> <71c4ce84-8be7-49e2-90bd-348762b320b4@nvidia.com> <34110c61-9826-4cbe-8cd4-76f5e7612dbd@nvidia.com> From: John Hubbard Message-ID: Date: Thu, 4 Feb 2021 22:41:14 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:85.0) Gecko/20100101 Thunderbird/85.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1612507275; bh=MVQPZX7CqWSAXEBpuiD9KIrZsqcSefGwB9+cJEmNR/U=; h=Subject:To:CC:References:From:Message-ID:Date:User-Agent: MIME-Version:In-Reply-To:Content-Type:Content-Language: Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy; b=ZFByrRMHweXhGS7HmqX+9r2j16FGVfJ0523O0aw40mEjjCqf7K2AucMH+RRnQ27JC +LlmYuuFNwD9ITf7dCQVWk0MJcfymXZI6xLvtraTM9qeoSG1fANpW/kXnwNYUhdeIF r57DT+MF6BGpsPTF/EIBscJmobATGHQ4uHuGWmgksjIyUnrYYft9Xdt5jHNMMADFDD OYJKTv1uRf3YFls9HvTopvWDcCIVngeRbJtCtPd3279I7Gn94/XkSMsqxo/hgu+G+l +53SVmSbWrx4re2Zew/yDEHji6Fw2YYXxNPqL4+qJj+iFt07EtqXTy+Wz0CLKRXZ05 ze5dYmvkPqx7A== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/4/21 10:24 PM, Minchan Kim wrote: > On Thu, Feb 04, 2021 at 09:49:54PM -0800, John Hubbard wrote: >> On 2/4/21 9:17 PM, Minchan Kim wrote: ... >> # cat vmstat | grep -i cma >> nr_free_cma 261718 >> >> # cat meminfo | grep -i cma >> CmaTotal: 1048576 kB >> CmaFree: 1046872 kB >> >> OK, given that CMA is already in those two locations, maybe we should put >> this information in one or both of those, yes? > > Do you suggest something liks this, for example? > > > cat vmstat | grep -i cma > cma_a_success 125 > cma_a_fail 25 > cma_b_success 130 > cma_b_fail 156 > .. > cma_f_fail xxx > Yes, approximately. I was wondering if this would suffice at least as a baseline: cma_alloc_success 125 cma_alloc_failure 25 ...and then, to see if more is needed, some questions: a) Do you know of an upper bound on how many cma areas there can be (I think Matthew also asked that)? b) Is tracking the cma area really as valuable as other possibilities? We can put "a few" to "several" items here, so really want to get your very favorite bits of information in. If, for example, there can be *lots* of cma areas, then maybe tracking by a range of allocation sizes is better... thanks, -- John Hubbard NVIDIA