From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by kanga.kvack.org (Postfix) with ESMTP id 577178E0001 for ; Wed, 19 Sep 2018 13:04:11 -0400 (EDT) Received: by mail-pg1-f198.google.com with SMTP id d132-v6so2639189pgc.22 for ; Wed, 19 Sep 2018 10:04:11 -0700 (PDT) Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com. [115.124.30.131]) by mx.google.com with ESMTPS id x3-v6si21452649pgo.542.2018.09.19.10.04.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 19 Sep 2018 10:04:09 -0700 (PDT) From: Yang Shi Subject: [v11 PATCH 2/3] mm: unmap VM_HUGETLB mappings with optimized path Date: Thu, 20 Sep 2018 01:03:40 +0800 Message-Id: <1537376621-51150-3-git-send-email-yang.shi@linux.alibaba.com> In-Reply-To: <1537376621-51150-1-git-send-email-yang.shi@linux.alibaba.com> References: <1537376621-51150-1-git-send-email-yang.shi@linux.alibaba.com> Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org, willy@infradead.org, ldufour@linux.vnet.ibm.com, vbabka@suse.cz, kirill@shutemov.name, akpm@linux-foundation.org Cc: dave.hansen@intel.com, oleg@redhat.com, srikar@linux.vnet.ibm.com, yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org When unmapping VM_HUGETLB mappings, vm flags need to be updated. Since the vmas have been detached, so it sounds safe to update vm flags with read mmap_sem. Cc: Michal Hocko Cc: Vlastimil Babka Reviewed-by: Matthew Wilcox Signed-off-by: Yang Shi --- mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mmap.c b/mm/mmap.c index 982dd00..490340e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2777,7 +2777,7 @@ static int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len, * update vm_flags. */ if (downgrade && - (tmp->vm_flags & (VM_HUGETLB | VM_PFNMAP))) + (tmp->vm_flags & VM_PFNMAP)) downgrade = false; tmp = tmp->vm_next; -- 1.8.3.1