From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 14FDA6B03E7 for ; Tue, 9 May 2017 04:42:36 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id p62so17600668wrc.13 for ; Tue, 09 May 2017 01:42:36 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id f142si240801wmf.45.2017.05.09.01.42.34 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 09 May 2017 01:42:34 -0700 (PDT) Subject: Re: [PATCH] mm: fix the memory leak after collapsing the huge page fails References: <1494317557-49680-1-git-send-email-zhongjiang@huawei.com> From: Vlastimil Babka Message-ID: <7d5fd103-f997-e445-2ce6-2e44deed33d8@suse.cz> Date: Tue, 9 May 2017 10:42:32 +0200 MIME-Version: 1.0 In-Reply-To: <1494317557-49680-1-git-send-email-zhongjiang@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: zhongjiang , akpm@linux-foundation.org Cc: mgorman@techsingularity.net, hannes@cmpxchg.org, kirill.shutemov@linux.intel.com, linux-mm@kvack.org On 05/09/2017 10:12 AM, zhongjiang wrote: > From: zhong jiang > > Current, when we prepare a huge page to collapse, due to some > reasons, it can fail to collapse. At the moment, we should > release the preallocate huge page. Yeah, looks like the leak is there... > Signed-off-by: zhong jiang > --- > mm/khugepaged.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 7cb9c88..3f5749e 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1080,6 +1080,7 @@ static void collapse_huge_page(struct mm_struct *mm, > result = SCAN_SUCCEED; > out_up_write: > up_write(&mm->mmap_sem); > + put_page(new_page); This doesn't seem correct. - the put_page() will be called also on success, so a premature free? - the out_nolock: case should be also handled - collapse_shmem() seems to have the same problem > out_nolock: > trace_mm_collapse_huge_page(mm, isolated, result); > return; > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org