From patchwork Thu Dec 1 13:50:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wonder_rock@126.com X-Patchwork-Id: 13061328 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5149C4321E for ; Thu, 1 Dec 2022 13:51:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5AEF56B0072; Thu, 1 Dec 2022 08:51:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 538376B0073; Thu, 1 Dec 2022 08:51:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3D7F76B0074; Thu, 1 Dec 2022 08:51:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 293B26B0072 for ; Thu, 1 Dec 2022 08:51:00 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id CC465AB762 for ; Thu, 1 Dec 2022 13:50:59 +0000 (UTC) X-FDA: 80193873438.22.0C2196B Received: from m15112.mail.126.com (m15112.mail.126.com [220.181.15.112]) by imf22.hostedemail.com (Postfix) with ESMTP id 679C7C0016 for ; Thu, 1 Dec 2022 13:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=BBFOF 5hbXkx5sANxzuB/pHT2CFFBu2rT2z2PtghB9cA=; b=pcXuO6Ud+cMl17jGdi4Jy 3AvIzyPm0mmbGZF6WXsDrl6uL10T5Ai7xjNV+Ug70rrdOSKmnSw/pTE2/qdvEaYA k3ai4XJ8Bv0i/2DaTWy+WA256Y9R8K9W31f0+8zf3U+RIQpQVNyyaha9i1t+/gEN BSZCbRjLw5BxfPgXug+/X0= Received: from localhost.localdomain (unknown [221.228.128.183]) by smtp2 (Coremail) with SMTP id DMmowABn7WE3sYhjaCrQEg--.8644S2; Thu, 01 Dec 2022 21:50:48 +0800 (CST) From: wonder_rock@126.com To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Deyan Wang Subject: [PATCH 1/1] mm/page_alloc: update comments in __free_pages_ok() Date: Thu, 1 Dec 2022 21:50:45 +0800 Message-Id: <20221201135045.31663-1-wonder_rock@126.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: DMmowABn7WE3sYhjaCrQEg--.8644S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrtFyruFWDKF1DZr1ktr17trb_yoWfXFcE9a 1qqry7ur4ftF9xKF47A3Z3JFyfKF18uryxuayftrZxtFy8ZFnrJa18JrnxCrWDWFs0gFWk GayvvFZrCw12gjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7sRZyCp3UUUUU== X-Originating-IP: [221.228.128.183] X-CM-SenderInfo: xzrqvv5ubu0ubn6rjloofrz/1tbiuRnKgVpD-Q7q3wAAs0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669902659; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=BBFOF5hbXkx5sANxzuB/pHT2CFFBu2rT2z2PtghB9cA=; b=A14Gg0wTtZjuH2tFY33xSAYAbMPtxN7b86MqDUqU4kDPiZUILqHqqqhWzfWQEQknV8Chu3 VYJliJn/soSiH6qqFEsTErTXTikssf/8BDKIitenRXddCPY0aV6NfBagnATGB+9SAIEhw/ U0cK23JCpAgfppDo+VjosnViLcloXFY= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=126.com header.s=s110527 header.b=pcXuO6Ud; spf=pass (imf22.hostedemail.com: domain of wonder_rock@126.com designates 220.181.15.112 as permitted sender) smtp.mailfrom=wonder_rock@126.com; dmarc=pass (policy=none) header.from=126.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669902659; a=rsa-sha256; cv=none; b=kHXCdoQ8KhpkvrSAr9FV7MhQfhwpNsWupbGnnzw+UFtJa7Qh0cuyX1XuEbmZgbjxRhd+Vz B9iPm1TrsBxJBKUN8SsmObdqmQaz2S/bhrIyoSMfwhUV4DgzeiyQCpnPBIir6oH9IdPvJc 9T6/0BIiPWO1jG4/vf/k8qL/Na+2SGs= X-Stat-Signature: 9apfyjyg5rmjraq1ricisto3ndtzaizk X-Rspam-User: X-Rspamd-Queue-Id: 679C7C0016 X-Rspamd-Server: rspam11 Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=126.com header.s=s110527 header.b=pcXuO6Ud; spf=pass (imf22.hostedemail.com: domain of wonder_rock@126.com designates 220.181.15.112 as permitted sender) smtp.mailfrom=wonder_rock@126.com; dmarc=pass (policy=none) header.from=126.com X-HE-Tag: 1669902658-179628 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: From: Deyan Wang Add a comment to explain why we call get_pfnblock_migratetype() twice in __free_pages_ok(). Signed-off-by: Deyan Wang --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2d4c81224508..52dd4fff280b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1702,6 +1702,11 @@ static void __free_pages_ok(struct page *page, unsigned int order, if (!free_pages_prepare(page, order, true, fpi_flags)) return; + /* + * Calling get_pfnblock_migratetype() without spin_lock_irqsave() here + * is used to avoid calling get_pfnblock_migratetype() under the lock. + * This will reduce the lock holding time. + */ migratetype = get_pfnblock_migratetype(page, pfn); spin_lock_irqsave(&zone->lock, flags);