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=-7.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 8055BC433E6 for ; Fri, 19 Mar 2021 13:46:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2ACBA64EEE for ; Fri, 19 Mar 2021 13:46:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2ACBA64EEE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BD72A6B007B; Fri, 19 Mar 2021 09:46:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B861B6B007D; Fri, 19 Mar 2021 09:46:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FE396B007E; Fri, 19 Mar 2021 09:46:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0206.hostedemail.com [216.40.44.206]) by kanga.kvack.org (Postfix) with ESMTP id 80E396B007B for ; Fri, 19 Mar 2021 09:46:00 -0400 (EDT) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 442E2180945DD for ; Fri, 19 Mar 2021 13:46:00 +0000 (UTC) X-FDA: 77936747238.31.F9F98CD Received: from mail-lf1-f43.google.com (mail-lf1-f43.google.com [209.85.167.43]) by imf09.hostedemail.com (Postfix) with ESMTP id 7D3E3600011F for ; Fri, 19 Mar 2021 13:45:59 +0000 (UTC) Received: by mail-lf1-f43.google.com with SMTP id o10so10077262lfb.9 for ; Fri, 19 Mar 2021 06:45:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=zm6BLtowGVk3+ISKouC1h9zvIkxos89pb8oEnL5NIS8=; b=d/nHmMhjTTMvsGTzLwH4k3vaY1L3wQH6aDBlMAsoOo40wtx7L3DTiTQ/eY7Y0rybbw QsiroprLBqmESHuM1Jv7zB8A6PswfeUGK0dbmGStvfK1HtPFQLv6SM6TCJXgDjXsrAk0 gQVKBfDiH+oiELc/fF1ROH/D2uG0mPeA5WmrOGttGJJ+hkpDXfsTd2s/nnhl4lidzz4F cmPDQ2F8XJK1gZzyJPRGtzcJJYoUUefhN2/b38kiMvoVOvhXjX/yFhqFhipEC4lhVI09 GN2IYAZVH+6m2pzsuc9RUpQFEU8dW+TGzK/twyqwJWQuWmMANe4u6G4ZV4/Knl2MMw9G gOKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=zm6BLtowGVk3+ISKouC1h9zvIkxos89pb8oEnL5NIS8=; b=tbmUAFaJ2euTSJ6poUHytkdTHqrWmkpa/7zd0jIpaKV1VToD35R6dIvghZtLoC9dNq LYU2GPUsk8YA7hjlzrq4QDgb/yxLZuY0HtHL368dc7dUiaxgkNOtilJZGj4YgMRE/WQ9 CmaHf+8m3e0IblUe2YythYBO+HvaqRpftyiXgJLGe8kvXw+EUu7MiyqMaM9CvEcMLBmn CGPRXpkqfYFUdGFCV2lBluVGYsRdxYtOCYGfIvaw60a80idJzn99wlpzZvmQq/gwHeGf ixI/sD3DLH7sIa+gmHiT1aKGnyCAFwE05zI7vr9wmIwtrfv+5S9I5eF8t8kME5FBpcf1 eKrg== X-Gm-Message-State: AOAM530tORBwFq2eXa8PXASVaHTLPGSMtxZ+2Qdi1qkMGZ0Hxtl7D36v QUS22JyZynp67y+SG2qcXuI= X-Google-Smtp-Source: ABdhPJz2cKbxJlDbrF6J4FeabfjuKDThfG1N2TnXEXdvR3+u57NbxcOc5w3UrRHNPQEHysr+vjWfNg== X-Received: by 2002:ac2:5149:: with SMTP id q9mr843384lfd.619.1616161558226; Fri, 19 Mar 2021 06:45:58 -0700 (PDT) Received: from [192.168.2.145] (109-252-193-52.dynamic.spd-mgts.ru. [109.252.193.52]) by smtp.googlemail.com with ESMTPSA id m22sm640702lfa.170.2021.03.19.06.45.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 19 Mar 2021 06:45:57 -0700 (PDT) Subject: Re: [PATCH v4] mm: cma: support sysfs From: Dmitry Osipenko To: Minchan Kim , Andrew Morton Cc: linux-mm , LKML , joaodias@google.com, willy@infradead.org, david@redhat.com, surenb@google.com, Greg Kroah-Hartman , John Hubbard , Nicolas Chauvet , "linux-tegra@vger.kernel.org" References: <20210309062333.3216138-1-minchan@kernel.org> Message-ID: <8d7ae527-e0ff-6fa9-7ba3-899a75abc3fa@gmail.com> Date: Fri, 19 Mar 2021 16:45:57 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Stat-Signature: r9ifz96sh4fi15kpbgmrssunkzu576mj X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7D3E3600011F Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf09; identity=mailfrom; envelope-from=""; helo=mail-lf1-f43.google.com; client-ip=209.85.167.43 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616161559-389096 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 19.03.2021 16:39, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > 19.03.2021 15:44, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > ... >>> #include >>> +#include >>> + >>> +struct cma_stat { >>> + spinlock_t lock; >>> + /* the number of CMA page successful allocations */ >>> + unsigned long nr_pages_succeeded; >>> + /* the number of CMA page allocation failures */ >>> + unsigned long nr_pages_failed; >>> + struct kobject kobj; >>> +}; >>> =20 >>> struct cma { >>> unsigned long base_pfn; >>> @@ -16,6 +26,9 @@ struct cma { >>> struct debugfs_u32_array dfs_bitmap; >>> #endif >>> char name[CMA_MAX_NAME]; >>> +#ifdef CONFIG_CMA_SYSFS >>> + struct cma_stat *stat; >>> +#endif >=20 > What is the point of allocating stat dynamically? >=20 > ... >>> +void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count) >>> +{ >>> + spin_lock(&cma->stat->lock); >>> + cma->stat->nr_pages_succeeded +=3D count; >>> + spin_unlock(&cma->stat->lock); >>> +} >>> + >>> +void cma_sysfs_fail_pages_count(struct cma *cma, size_t count) >>> +{ >>> + spin_lock(&cma->stat->lock); >>> + cma->stat->nr_pages_failed +=3D count; >>> + spin_unlock(&cma->stat->lock); >>> +} >=20 > You could use atomic increment and then locking isn't needed. >=20 Actually, the counter should be u64 in order not to worry about overflow.