From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f182.google.com (mail-ig0-f182.google.com [209.85.213.182]) by kanga.kvack.org (Postfix) with ESMTP id 9EDF66B0032 for ; Thu, 9 Apr 2015 10:06:01 -0400 (EDT) Received: by iggg4 with SMTP id g4so67264308igg.0 for ; Thu, 09 Apr 2015 07:06:01 -0700 (PDT) Received: from smtp.codeaurora.org (smtp.codeaurora.org. [198.145.29.96]) by mx.google.com with ESMTPS id ke17si2599532icb.92.2015.04.09.07.06.01 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Apr 2015 07:06:01 -0700 (PDT) Message-ID: <55268741.8010301@codeaurora.org> Date: Thu, 09 Apr 2015 19:35:53 +0530 From: Susheel Khiani MIME-Version: 1.0 Subject: [Question] ksm: rmap_item pointing to some stale vmas Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, peterz@infradead.org, neilb@suse.de, dhowells@redhat.com, hughd@google.com, paulmcquad@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi, We are seeing an issue during try_to_unmap_ksm where in call to try_to_unmap_one is failing. try_to_unmap_ksm in this particular case is trying to go through vmas associated with each rmap_item->anon_vma. What we see is this that the corresponding page is not mapped to any of the vmas associated with 2 rmap_item. The associated rmap_item in this case looks like pointing to some valid vma but the said page is not found to be mapped under it. try_to_unmap_one thus fails to find valid ptes for these vmas. At the same time we can see that the page actually is mapped in 2 separate and different vmas which are not part of rmap_item associated with page. So whether rmap_item is pointing to some stale vmas and now the mapping has changed? Or there is something else going on here. p Any pointer would be appreciated. -- Susheel Khiani QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- 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