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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54E5EC433EF for ; Tue, 15 Mar 2022 04:24:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344765AbiCOEZt (ORCPT ); Tue, 15 Mar 2022 00:25:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238573AbiCOEZr (ORCPT ); Tue, 15 Mar 2022 00:25:47 -0400 Received: from spam.unicloud.com (smgmail.unigroup.com.cn [220.194.70.58]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D71631FCDF for ; Mon, 14 Mar 2022 21:24:33 -0700 (PDT) Received: from eage.unicloud.com ([220.194.70.35]) by spam.unicloud.com with ESMTP id 22F4OAbb021710; Tue, 15 Mar 2022 12:24:10 +0800 (GMT-8) (envelope-from luofei@unicloud.com) Received: from localhost.localdomain (10.10.1.7) by zgys-ex-mb09.Unicloud.com (10.10.0.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2375.17; Tue, 15 Mar 2022 12:24:09 +0800 From: luofei To: , CC: , , luofei Subject: [PATCH] hugetlbfs: fix description about atomic allocation of vmemmap pages when free huge page Date: Tue, 15 Mar 2022 00:23:55 -0400 Message-ID: <20220315042355.362810-1-luofei@unicloud.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.10.1.7] X-ClientProxiedBy: zgys-ex-mb10.Unicloud.com (10.10.0.6) To zgys-ex-mb09.Unicloud.com (10.10.0.24) X-DNSRBL: X-MAIL: spam.unicloud.com 22F4OAbb021710 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org No matter what context update_and_free_page() is called in, the flag for allocating the vmemmap page is fixed (GFP_KERNEL | __GFP_NORETRY | __GFP_THISNODE), and no atomic allocation is involved, so the description of atomicity here is somewhat inappropriate. and the atomic parameter naming of update_and_free_page() is somewhat misleading. Signed-off-by: luofei --- mm/hugetlb.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f8ca7cca3c1a..239ef82b7897 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1570,8 +1570,8 @@ static void __update_and_free_page(struct hstate *h, struct page *page) /* * As update_and_free_page() can be called under any context, so we cannot - * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the - * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate + * use GFP_ATOMIC to allocate vmemmap pages. However, we can defer the + * actual freeing in a workqueue to prevent waits caused by allocating * the vmemmap pages. * * free_hpage_workfn() locklessly retrieves the linked list of pages to be @@ -1617,16 +1617,14 @@ static inline void flush_free_hpage_work(struct hstate *h) } static void update_and_free_page(struct hstate *h, struct page *page, - bool atomic) + bool delay) { - if (!HPageVmemmapOptimized(page) || !atomic) { + if (!HPageVmemmapOptimized(page) || !delay) { __update_and_free_page(h, page); return; } /* - * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. - * * Only call schedule_work() if hpage_freelist is previously * empty. Otherwise, schedule_work() had been called but the workfn * hasn't retrieved the list yet. -- 2.27.0