From patchwork Sat Jun 11 02:13:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12878312 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 33B2CC433EF for ; Sat, 11 Jun 2022 02:14:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 551156B0136; Fri, 10 Jun 2022 22:14:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4FFD66B0138; Fri, 10 Jun 2022 22:14:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3C7A16B0139; Fri, 10 Jun 2022 22:14:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 2D2AE6B0136 for ; Fri, 10 Jun 2022 22:14:02 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id F0F2A120222 for ; Sat, 11 Jun 2022 02:14:01 +0000 (UTC) X-FDA: 79564334682.28.4F6485A Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf06.hostedemail.com (Postfix) with ESMTP id 460E018006D for ; Sat, 11 Jun 2022 02:14:01 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LKhBT220kzRhrQ; Sat, 11 Jun 2022 10:10:41 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 11 Jun 2022 10:13:49 +0800 From: Miaohe Lin To: CC: , , , Subject: [PATCH v2] mm/page_alloc: minor clean up for memmap_init_compound() Date: Sat, 11 Jun 2022 10:13:52 +0800 Message-ID: <20220611021352.13529-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1654913641; a=rsa-sha256; cv=none; b=z+8+Qrs8N5TWi9CW8fjw5FsP84+zVOa7TMfIVCg2rwO3NAaIPJId6yJtL3NAvAIWiSeQ01 tN+mFppkG6YdcnUHwSOVtPdVgSdVVni2Tkd5JQw7kiEl7J0LO4VRhvbBAu6MYZOwlpSWsd jpJZcPKMuDujeFrNqNroj8ofHTTUj6g= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1654913641; 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-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=SMNlBnxMaOrji6qJDW++SzcVZBhf2jC4zqdPqgbWYTs=; b=5Kq15J97o3IVjP9VL9ivR641U4tWz/x8xXCkQ5UlGmjC0OjPAAP54l2s8ht9IblczmUMSm gAl5gmAZjXys2vs1MgrpZ78vkx1CcpJp7Oc5ecIrZ/7a9ZIhqx0vzkV5t7+BPP/q+Vfbkq eCKYUHGsxI1/bw7n7UCQP2uOMEnFScU= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 460E018006D X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Stat-Signature: aeoknaxzg3w839jfpagamrn3fqwnzk95 X-HE-Tag: 1654913641-646098 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: Since commit 5232c63f46fd ("mm: Make compound_pincount always available"), compound_pincount_ptr is stored at first tail page now. So we should call prep_compound_head() after the first tail page is initialized to take advantage of the likelihood of that tail struct page being cached given that we will read them right after in prep_compound_head(). Signed-off-by: Miaohe Lin Cc: Joao Martins --- v2: Don't move prep_compound_head() outside loop per Joao. --- mm/page_alloc.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4c7d99ee58b4..048df5d78add 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6771,13 +6771,18 @@ static void __ref memmap_init_compound(struct page *head, set_page_count(page, 0); /* - * The first tail page stores compound_mapcount_ptr() and - * compound_order() and the second tail page stores - * compound_pincount_ptr(). Call prep_compound_head() after - * the first and second tail pages have been initialized to - * not have the data overwritten. + * The first tail page stores compound_mapcount_ptr(), + * compound_order() and compound_pincount_ptr(). Call + * prep_compound_head() after the first tail page have + * been initialized to not have the data overwritten. + * + * Note the idea to make this right after we initialize + * the offending tail pages is trying to take advantage + * of the likelihood of those tail struct pages being + * cached given that we will read them right after in + * prep_compound_head(). */ - if (pfn == head_pfn + 2) + if (unlikely(pfn == head_pfn + 1)) prep_compound_head(head, order); } }