From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 558B4C2BA18 for ; Mon, 6 Apr 2020 08:19:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E8B220672 for ; Mon, 6 Apr 2020 08:19:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbgDFITG (ORCPT ); Mon, 6 Apr 2020 04:19:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:39878 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726475AbgDFITF (ORCPT ); Mon, 6 Apr 2020 04:19:05 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 8BC5CAB7F; Mon, 6 Apr 2020 08:19:03 +0000 (UTC) Subject: Re: [PATCH -V3] /proc/PID/smaps: Add PMD migration entry parsing To: "Huang, Ying" , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zi Yan , Andrea Arcangeli , "Kirill A . Shutemov" , Alexey Dobriyan , Michal Hocko , Konstantin Khlebnikov , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Yang Shi References: <20200403123059.1846960-1-ying.huang@intel.com> From: Vlastimil Babka Message-ID: <7308c5a2-a24e-85ee-7496-99cd28053af4@suse.cz> Date: Mon, 6 Apr 2020 10:19:02 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200403123059.1846960-1-ying.huang@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/3/20 2:30 PM, Huang, Ying wrote: > From: Huang Ying > > Now, when read /proc/PID/smaps, the PMD migration entry in page table is simply > ignored. To improve the accuracy of /proc/PID/smaps, its parsing and processing > is added. > > To test the patch, we run pmbench to eat 400 MB memory in background, then run > /usr/bin/migratepages and `cat /proc/PID/smaps` every second. The issue as > follows can be reproduced within 60 seconds. > > Before the patch, for the fully populated 400 MB anonymous VMA, some THP pages > under migration may be lost as below. > > 7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0 > Size: 409600 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > Rss: 407552 kB > Pss: 407552 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 407552 kB > Referenced: 301056 kB > Anonymous: 407552 kB > LazyFree: 0 kB > AnonHugePages: 405504 kB > ShmemPmdMapped: 0 kB > FilePmdMapped: 0 kB > Shared_Hugetlb: 0 kB > Private_Hugetlb: 0 kB > Swap: 0 kB > SwapPss: 0 kB > Locked: 0 kB > THPeligible: 1 > VmFlags: rd wr mr mw me ac > > After the patch, it will be always, > > 7f3f6a7e5000-7f3f837e5000 rw-p 00000000 00:00 0 > Size: 409600 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > Rss: 409600 kB > Pss: 409600 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 409600 kB > Referenced: 294912 kB > Anonymous: 409600 kB > LazyFree: 0 kB > AnonHugePages: 407552 kB > ShmemPmdMapped: 0 kB > FilePmdMapped: 0 kB > Shared_Hugetlb: 0 kB > Private_Hugetlb: 0 kB > Swap: 0 kB > SwapPss: 0 kB > Locked: 0 kB > THPeligible: 1 > VmFlags: rd wr mr mw me ac > > Signed-off-by: "Huang, Ying" > Reviewed-by: Zi Yan > Cc: Andrea Arcangeli > Cc: Kirill A. Shutemov > Cc: Vlastimil Babka > Cc: Alexey Dobriyan > Cc: Michal Hocko > Cc: Konstantin Khlebnikov > Cc: "Jérôme Glisse" > Cc: Yang Shi Acked-by: Vlastimil Babka Thanks!