From patchwork Wed Jul 8 09:50:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Yang X-Patchwork-Id: 11651231 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3B62960D for ; Wed, 8 Jul 2020 09:50:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 11B3F20720 for ; Wed, 8 Jul 2020 09:50:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11B3F20720 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 945978D003B; Wed, 8 Jul 2020 05:50:51 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8CE118D000D; Wed, 8 Jul 2020 05:50:51 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 76C708D0040; Wed, 8 Jul 2020 05:50:51 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0127.hostedemail.com [216.40.44.127]) by kanga.kvack.org (Postfix) with ESMTP id 5AC128D003B for ; Wed, 8 Jul 2020 05:50:51 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 267CD180AD81A for ; Wed, 8 Jul 2020 09:50:51 +0000 (UTC) X-FDA: 77014439502.28.front90_620216f26ebc Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id E7D256D83 for ; Wed, 8 Jul 2020 09:50:50 +0000 (UTC) X-Spam-Summary: 1,0,0,96a6f42f33324101,d41d8cd98f00b204,richard.weiyang@linux.alibaba.com,,RULES_HIT:41:355:379:541:800:960:973:988:989:1260:1261:1311:1314:1345:1359:1437:1515:1535:1543:1711:1730:1747:1777:1792:2393:2559:2562:3138:3139:3140:3141:3142:3354:3865:3867:3868:3870:3871:4321:4605:5007:6261:6737:7514:10004:11026:11473:11658:11914:12043:12048:12296:12297:12438:12555:12895:12986:13161:13229:13255:13894:14181:14721:21080:21451:21627:21990:30054:30065:30070,0,RBL:115.124.30.45:@linux.alibaba.com:.lbl8.mailshell.net-64.201.201.201 62.20.2.100;04yr5z6kdmzxqdnxwkghtgebtmxxxoc11xpmzk139zpr39jbz1kdzk4eyo1i44o.ppduhp14wjxhdui53gf7zbrs5akijqbpkucsnef7d3f4xspzs918tmhcikfd8d4.r-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: front90_620216f26ebc X-Filterd-Recvd-Size: 5200 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Wed, 8 Jul 2020 09:50:49 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=richard.weiyang@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0U26d6gP_1594201843; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0U26d6gP_1594201843) by smtp.aliyun-inc.com(127.0.0.1); Wed, 08 Jul 2020 17:50:43 +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 v4 1/4] mm/mremap: it is sure to have enough space when extent meets requirement Date: Wed, 8 Jul 2020 17:50:25 +0800 Message-Id: <20200708095028.41706-2-richard.weiyang@linux.alibaba.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20200708095028.41706-1-richard.weiyang@linux.alibaba.com> References: <20200708095028.41706-1-richard.weiyang@linux.alibaba.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: E7D256D83 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: old_end is passed to these two function to check whether there is enough space to do the move, while this check is done before invoking these functions. These two functions only would be invoked when extent meets the requirement and there is one check before invoking these functions: if (extent > old_end - old_addr) extent = old_end - old_addr; This implies (old_end - old_addr) won't fail the check in these two functions. Signed-off-by: Wei Yang Tested-by: Dmitry Osipenko Acked-by: Kirill A. Shutemov --- include/linux/huge_mm.h | 2 +- mm/huge_memory.c | 7 ++----- mm/mremap.c | 10 ++++------ 3 files changed, 7 insertions(+), 12 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 71f20776b06c..17c4c4975145 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -42,7 +42,7 @@ extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, unsigned char *vec); extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd); extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 78c84bee7e29..1e580fdad4d0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1722,17 +1722,14 @@ static pmd_t move_soft_dirty_pmd(pmd_t pmd) } bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd) + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) { spinlock_t *old_ptl, *new_ptl; pmd_t pmd; struct mm_struct *mm = vma->vm_mm; bool force_flush = false; - if ((old_addr & ~HPAGE_PMD_MASK) || - (new_addr & ~HPAGE_PMD_MASK) || - old_end - old_addr < HPAGE_PMD_SIZE) + if ((old_addr & ~HPAGE_PMD_MASK) || (new_addr & ~HPAGE_PMD_MASK)) return false; /* diff --git a/mm/mremap.c b/mm/mremap.c index 5dd572d57ca9..de27b12c8a5a 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -193,15 +193,13 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, #ifdef CONFIG_HAVE_MOVE_PMD static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, - unsigned long new_addr, unsigned long old_end, - pmd_t *old_pmd, pmd_t *new_pmd) + unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) { spinlock_t *old_ptl, *new_ptl; struct mm_struct *mm = vma->vm_mm; pmd_t pmd; - if ((old_addr & ~PMD_MASK) || (new_addr & ~PMD_MASK) - || old_end - old_addr < PMD_SIZE) + if ((old_addr & ~PMD_MASK) || (new_addr & ~PMD_MASK)) return false; /* @@ -273,7 +271,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_huge_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd); + old_pmd, new_pmd); if (need_rmap_locks) drop_rmap_locks(vma); if (moved) @@ -293,7 +291,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_normal_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd); + old_pmd, new_pmd); if (need_rmap_locks) drop_rmap_locks(vma); if (moved)