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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D756EC433F5 for ; Fri, 6 May 2022 03:01:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 584776B0071; Thu, 5 May 2022 23:01:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 50C876B0073; Thu, 5 May 2022 23:01:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 386926B0074; Thu, 5 May 2022 23:01:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 26D496B0071 for ; Thu, 5 May 2022 23:01:54 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id F24988096C for ; Fri, 6 May 2022 03:01:53 +0000 (UTC) X-FDA: 79433818506.03.0A1E912 Received: from out199-14.us.a.mail.aliyun.com (out199-14.us.a.mail.aliyun.com [47.90.199.14]) by imf03.hostedemail.com (Postfix) with ESMTP id 3D0AF20019 for ; Fri, 6 May 2022 03:01:45 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=30;SR=0;TI=SMTPD_---0VCQ-60L_1651806089; Received: from 30.32.96.193(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VCQ-60L_1651806089) by smtp.aliyun-inc.com(127.0.0.1); Fri, 06 May 2022 11:01:31 +0800 Message-ID: <6c8a5b23-e470-63ca-cc82-f8b5ff1bafaf@linux.alibaba.com> Date: Fri, 6 May 2022 11:02:12 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH 1/3] mm: change huge_ptep_clear_flush() to return the original pte To: Mike Kravetz , akpm@linux-foundation.org, catalin.marinas@arm.com, will@kernel.org Cc: tsbogend@alpha.franken.de, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org References: <495c4ebe-a5b4-afb6-4cb0-956c1b18d0cc@oracle.com> From: Baolin Wang In-Reply-To: <495c4ebe-a5b4-afb6-4cb0-956c1b18d0cc@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Authentication-Results: imf03.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf03.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 47.90.199.14 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 3D0AF20019 X-Rspam-User: X-Stat-Signature: sxwj4skb5ffd7uukqxynktz98ye8hmfe X-HE-Tag: 1651806105-58396 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 5/6/2022 7:15 AM, Mike Kravetz wrote: > On 4/29/22 01:14, Baolin Wang wrote: >> It is incorrect to use ptep_clear_flush() to nuke a hugetlb page >> table when unmapping or migrating a hugetlb page, and will change >> to use huge_ptep_clear_flush() instead in the following patches. >> >> So this is a preparation patch, which changes the huge_ptep_clear_flush() >> to return the original pte to help to nuke a hugetlb page table. >> >> Signed-off-by: Baolin Wang >> --- >> arch/arm64/include/asm/hugetlb.h | 4 ++-- >> arch/arm64/mm/hugetlbpage.c | 12 +++++------- >> arch/ia64/include/asm/hugetlb.h | 4 ++-- >> arch/mips/include/asm/hugetlb.h | 9 ++++++--- >> arch/parisc/include/asm/hugetlb.h | 4 ++-- >> arch/powerpc/include/asm/hugetlb.h | 9 ++++++--- >> arch/s390/include/asm/hugetlb.h | 6 +++--- >> arch/sh/include/asm/hugetlb.h | 4 ++-- >> arch/sparc/include/asm/hugetlb.h | 4 ++-- >> include/asm-generic/hugetlb.h | 4 ++-- >> 10 files changed, 32 insertions(+), 28 deletions(-) > > The above changes look straight forward. > Happy that you Cc'ed impacted arch maintainers so they can at least > have a look. > > The only user of huge_ptep_clear_flush() today is hugetlb_cow/wp() in > mm/hugetlb.c. Any reason why you did not change that code? At least Cause we did not use the return value of huge_ptep_clear_flush() in mm/hugetlb.c. > cast the return of huge_ptep_clear_flush() to void with a comment? Sure. Will add an explicit casting in next version. > Not absolutely necessary. > > Acked-by: Mike Kravetz Thanks.