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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 3F8EBC10F14 for ; Thu, 18 Apr 2019 20:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19BA920869 for ; Thu, 18 Apr 2019 20:17:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390027AbfDRURS (ORCPT ); Thu, 18 Apr 2019 16:17:18 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:49920 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728181AbfDRURR (ORCPT ); Thu, 18 Apr 2019 16:17:17 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0TPfSgC1_1555618625; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TPfSgC1_1555618625) by smtp.aliyun-inc.com(127.0.0.1); Fri, 19 Apr 2019 04:17:13 +0800 From: Yang Shi To: mhocko@suse.com, kirill.shutemov@linux.intel.com, ziy@nvidia.com, rppt@linux.vnet.ibm.com, corbet@lwn.net, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] doc: mm: migration doesn't use FOLL_SPLIT anymore Date: Fri, 19 Apr 2019 04:17:04 +0800 Message-Id: <1555618624-23957-1-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When demonstrating FOLL_SPLIT in transhuge document, migration is used as an example. But, since commit 94723aafb9e7 ("mm: unclutter THP migration"), the way of THP migration is totally changed. FOLL_SPLIT is not used by migration anymore due to the change. Remove the obsolete example to avoid confusion. Cc: Michal Hocko Cc: Kirill A. Shutemov Cc: Zi Yan Cc: Mike Rapoport Signed-off-by: Yang Shi --- Documentation/vm/transhuge.rst | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/Documentation/vm/transhuge.rst b/Documentation/vm/transhuge.rst index a8cf680..8df3806 100644 --- a/Documentation/vm/transhuge.rst +++ b/Documentation/vm/transhuge.rst @@ -55,13 +55,7 @@ prevent page from being split by anyone. In case you can't handle compound pages if they're returned by follow_page, the FOLL_SPLIT bit can be specified as parameter to follow_page, so that it will split the hugepages before returning -them. Migration for example passes FOLL_SPLIT as parameter to -follow_page because it's not hugepage aware and in fact it can't work -at all on hugetlbfs (but it instead works fine on transparent -hugepages thanks to FOLL_SPLIT). migration simply can't deal with -hugepages being returned (as it's not only checking the pfn of the -page and pinning it during the copy but it pretends to migrate the -memory in regular page sizes and with regular pte/pmd mappings). +them. Graceful fallback ================= -- 1.8.3.1