From patchwork Fri Jan 15 09:20:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12021957 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 C334BC433E0 for ; Fri, 15 Jan 2021 09:20:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 257E1221F7 for ; Fri, 15 Jan 2021 09:20:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 257E1221F7 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 5AAC88D0145; Fri, 15 Jan 2021 04:20:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5339C8D0023; Fri, 15 Jan 2021 04:20:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4227A8D0145; Fri, 15 Jan 2021 04:20:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0176.hostedemail.com [216.40.44.176]) by kanga.kvack.org (Postfix) with ESMTP id 281A28D0023 for ; Fri, 15 Jan 2021 04:20:39 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E1CCBA76D for ; Fri, 15 Jan 2021 09:20:38 +0000 (UTC) X-FDA: 77707464156.14.bait59_281694a2752e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id C573218229835 for ; Fri, 15 Jan 2021 09:20:38 +0000 (UTC) X-HE-Tag: bait59_281694a2752e X-Filterd-Recvd-Size: 1945 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Fri, 15 Jan 2021 09:20:37 +0000 (UTC) Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4DHFxl3l02zj6rd; Fri, 15 Jan 2021 17:19:39 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.498.0; Fri, 15 Jan 2021 17:20:20 +0800 From: Miaohe Lin To: , CC: , , , Subject: [PATCH v2] mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call Date: Fri, 15 Jan 2021 04:20:13 -0500 Message-ID: <20210115092013.61012-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected 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: When gbl_reserve is 0, hugetlb_acct_memory() will do nothing except holding and releasing hugetlb_lock. We should avoid this unnecessary hugetlb_lock lock/unlock cycle which is happening on 'most' hugetlb munmap operations by check delta against 0 at the beginning of hugetlb_acct_memory. Reviewed-by: David Hildenbrand Signed-off-by: Miaohe Lin Reviewed-by: Oscar Salvador --- mm/hugetlb.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4f67f6b159c7..da064cb8fd53 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3591,6 +3591,9 @@ static int hugetlb_acct_memory(struct hstate *h, long delta) { int ret = -ENOMEM; + if (!delta) + return 0; + spin_lock(&hugetlb_lock); /* * When cpuset is configured, it breaks the strict hugetlb page