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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 0DBFAC433E0 for ; Thu, 4 Mar 2021 07:43:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 59C1364EFC for ; Thu, 4 Mar 2021 07:43:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59C1364EFC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EED026B0007; Thu, 4 Mar 2021 02:43:02 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EC3D36B0008; Thu, 4 Mar 2021 02:43:02 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D8C576B000C; Thu, 4 Mar 2021 02:43:02 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0095.hostedemail.com [216.40.44.95]) by kanga.kvack.org (Postfix) with ESMTP id C03586B0007 for ; Thu, 4 Mar 2021 02:43:02 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7B8CB1801E31E for ; Thu, 4 Mar 2021 07:43:02 +0000 (UTC) X-FDA: 77881400604.28.32A3963 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) by imf09.hostedemail.com (Postfix) with ESMTP id 4B15A6000100 for ; Thu, 4 Mar 2021 07:43:00 +0000 (UTC) Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4DrjVM2BJyzjV7R; Thu, 4 Mar 2021 15:41:31 +0800 (CST) Received: from huawei.com (10.175.112.208) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.498.0; Thu, 4 Mar 2021 15:42:44 +0800 From: Zhou Guanghui To: , CC: , , , , , , , , , , , Subject: [PATCH v2 2/2] mm/memcg: set memcg when split page Date: Thu, 4 Mar 2021 07:40:53 +0000 Message-ID: <20210304074053.65527-3-zhouguanghui1@huawei.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20210304074053.65527-1-zhouguanghui1@huawei.com> References: <20210304074053.65527-1-zhouguanghui1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.112.208] X-CFilter-Loop: Reflected X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 4B15A6000100 X-Stat-Signature: 59kq4o4ksswd1e7pmkhs5arrginb53hp Received-SPF: none (huawei.com>: No applicable sender policy available) receiver=imf09; identity=mailfrom; envelope-from=""; helo=szxga06-in.huawei.com; client-ip=45.249.212.32 X-HE-DKIM-Result: none/none X-HE-Tag: 1614843780-923671 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: As described in the split_page function comment, for the non-compound high order page, the sub-pages must be freed individually. If the memcg of the fisrt page is valid, the tail pages cannot be uncharged when be freed. For example, when alloc_pages_exact is used to allocate 1MB continuous physical memory, 2MB is charged(kmemcg is enabled and __GFP_ACCOUNT is set). When make_alloc_exact free the unused 1MB and free_pages_exact free the applied 1MB, actually, only 4KB(one page) is uncharged. Therefore, the memcg of the tail page needs to be set when split page. Signed-off-by: Zhou Guanghui --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3e4b29ee2b1e..3ed783e25c3c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3310,6 +3310,7 @@ void split_page(struct page *page, unsigned int ord= er) for (i =3D 1; i < (1 << order); i++) set_page_refcounted(page + i); split_page_owner(page, 1 << order); + split_page_memcg(page, 1 << order); } EXPORT_SYMBOL_GPL(split_page); =20 --=20 2.25.0