From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 863716B025F for ; Thu, 2 Jun 2016 09:13:55 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id f75so27274021wmf.2 for ; Thu, 02 Jun 2016 06:13:55 -0700 (PDT) Received: from mail-wm0-f67.google.com (mail-wm0-f67.google.com. [74.125.82.67]) by mx.google.com with ESMTPS id e14si1347004wmd.17.2016.06.02.06.13.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 Jun 2016 06:13:54 -0700 (PDT) Received: by mail-wm0-f67.google.com with SMTP id a20so4182279wma.3 for ; Thu, 02 Jun 2016 06:13:54 -0700 (PDT) Date: Thu, 2 Jun 2016 15:13:53 +0200 From: Michal Hocko Subject: Re: [linux-next-20160602] kernel BUG at mm/rmap.c:1253! Message-ID: <20160602131352.GQ1995@dhcp22.suse.cz> References: <201606022014.GFF87050.FJOLVOMQHFOtSF@I-love.SAKURA.ne.jp> <20160602115046.GA2001@dhcp22.suse.cz> <20160602115949.GL1995@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160602115949.GL1995@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: linux-mm@kvack.org, Andrea Arcangeli , "Kirill A. Shutemov" , Ebru Akagunduz On Thu 02-06-16 13:59:49, Michal Hocko wrote: > [CCing Ebru] > > On Thu 02-06-16 13:50:46, Michal Hocko wrote: > > [CCing Andrea and Kirill] > > Hmm, thinking about it little bit more it might be related to "mm, thp: > make swapin readahead under down_read of mmap_sem". I didn't get to look > closer at the patch but maybe revalidate after mmap sem is dropped is > not sufficient. so hugepage_vma_revalidate does this: hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (address < hstart || address + HPAGE_PMD_SIZE > hend) return SCAN_ADDRESS_RANGE; I really do not see why we have to play with hstart and hend. But address + HPAGE_PMD_SIZE > hend part looks suspicious. address always have to vm_start <= address && address < vm_end AFAICS. and the above allows address + HPAGE_PMD_MASK == end. -- Michal Hocko SUSE Labs -- 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