From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id 4D6A92803C7 for ; Tue, 9 May 2017 07:34:13 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id u96so18972324wrc.7 for ; Tue, 09 May 2017 04:34:13 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id x65si18471888wrb.290.2017.05.09.04.34.11 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 09 May 2017 04:34:12 -0700 (PDT) Subject: Re: [PATCH v2] mm: fix the memory leak after collapsing the huge page fails References: <1494327305-835-1-git-send-email-zhongjiang@huawei.com> From: Vlastimil Babka Message-ID: <442638e9-d6db-2f1c-e260-9290d7524f1d@suse.cz> Date: Tue, 9 May 2017 13:34:10 +0200 MIME-Version: 1.0 In-Reply-To: <1494327305-835-1-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: kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, mgorman@techsingularity.net, linux-mm@kvack.org On 05/09/2017 12:55 PM, 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. > > Signed-off-by: zhong jiang Hmm, scratch that, there's no memory leak. The pointer to new_page is stored in *hpage, and put_page() is called all the way up in khugepaged_do_scan(). > --- > mm/khugepaged.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 7cb9c88..586b1f1 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1082,6 +1082,8 @@ static void collapse_huge_page(struct mm_struct *mm, > up_write(&mm->mmap_sem); > out_nolock: > trace_mm_collapse_huge_page(mm, isolated, result); > + if (page != NULL && result != SCAN_SUCCEED) > + put_page(new_page); > return; > out: > mem_cgroup_cancel_charge(new_page, memcg, true); > @@ -1555,6 +1557,8 @@ static void collapse_shmem(struct mm_struct *mm, > } > out: > VM_BUG_ON(!list_empty(&pagelist)); > + if (page != NULL && result != SCAN_SUCCEED) > + put_page(new_page); > /* TODO: tracepoints */ > } > > -- 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