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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 55EF8C433DF for ; Wed, 8 Jul 2020 01:26:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A26320708 for ; Wed, 8 Jul 2020 01:26:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A26320708 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B89358D0011; Tue, 7 Jul 2020 21:25:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B390B8D0003; Tue, 7 Jul 2020 21:25:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4F738D0011; Tue, 7 Jul 2020 21:25:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0166.hostedemail.com [216.40.44.166]) by kanga.kvack.org (Postfix) with ESMTP id 8E0428D0003 for ; Tue, 7 Jul 2020 21:25:59 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 4C0B18248D51 for ; Wed, 8 Jul 2020 01:25:59 +0000 (UTC) X-FDA: 77013167238.03.rest50_100c42126eb9 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 1846B28A4E9 for ; Wed, 8 Jul 2020 01:25:59 +0000 (UTC) X-HE-Tag: rest50_100c42126eb9 X-Filterd-Recvd-Size: 3131 Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Wed, 8 Jul 2020 01:25:58 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=richard.weiyang@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0U24OO8d_1594171544; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0U24OO8d_1594171544) by smtp.aliyun-inc.com(127.0.0.1); Wed, 08 Jul 2020 09:25:44 +0800 From: Wei Yang To: akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, vbabka@suse.cz, yang.shi@linux.alibaba.com, thomas_os@shipmail.org, anshuman.khandual@arm.com, sean.j.christopherson@intel.com, richard.weiyang@linux.alibaba.com, peterx@redhat.com, aneesh.kumar@linux.ibm.com, willy@infradead.org, thellstrom@vmware.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, digetx@gmail.com Subject: [Patch v3 2/4] mm/mremap: calculate extent in one place Date: Wed, 8 Jul 2020 09:24:51 +0800 Message-Id: <20200708012453.36588-3-richard.weiyang@linux.alibaba.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20200708012453.36588-1-richard.weiyang@linux.alibaba.com> References: <20200708012453.36588-1-richard.weiyang@linux.alibaba.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 1846B28A4E9 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 Content-Transfer-Encoding: quoted-printable 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: Page tables is moved on the base of PMD. This requires both source and destination range should meet the requirement. Current code works well since move_huge_pmd() and move_normal_pmd() would check old_addr and new_addr again. And then return to move_ptes() if the either of them is not aligned. In stead of calculating the extent separately, it is better to calculate in one place, so we know it is not necessary to try move pmd. By doing so, the logic seems a little clear. Signed-off-by: Wei Yang Tested-by: Dmitry Osipenko Acked-by: Kirill A. Shutemov --- mm/mremap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index de27b12c8a5a..a30b3e86cc99 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -258,6 +258,9 @@ unsigned long move_page_tables(struct vm_area_struct = *vma, extent =3D next - old_addr; if (extent > old_end - old_addr) extent =3D old_end - old_addr; + next =3D (new_addr + PMD_SIZE) & PMD_MASK; + if (extent > next - new_addr) + extent =3D next - new_addr; old_pmd =3D get_old_pmd(vma->vm_mm, old_addr); if (!old_pmd) continue; @@ -301,9 +304,6 @@ unsigned long move_page_tables(struct vm_area_struct = *vma, =20 if (pte_alloc(new_vma->vm_mm, new_pmd)) break; - next =3D (new_addr + PMD_SIZE) & PMD_MASK; - if (extent > next - new_addr) - extent =3D next - new_addr; move_ptes(vma, old_pmd, old_addr, old_addr + extent, new_vma, new_pmd, new_addr, need_rmap_locks); } --=20 2.20.1 (Apple Git-117)