From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 761C16B0003 for ; Thu, 21 Jun 2018 18:50:05 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id s7-v6so2188216pfm.4 for ; Thu, 21 Jun 2018 15:50:05 -0700 (PDT) Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com. [115.124.30.133]) by mx.google.com with ESMTPS id m11-v6si5869720plt.284.2018.06.21.15.50.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Jun 2018 15:50:04 -0700 (PDT) Subject: Re: [PATCH] mm: thp: register mm for khugepaged when merging vma for shmem From: Yang Shi References: <1529617247-126312-1-git-send-email-yang.shi@linux.alibaba.com> <20180621221008.r33hpd223kx2gv3a@kshutemo-mobl1> Message-ID: <8a411d2f-1765-beb2-0850-73feaa7ba79b@linux.alibaba.com> Date: Thu, 21 Jun 2018 15:49:58 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: hughd@google.com, kirill.shutemov@linux.intel.com, vbabka@suse.cz, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 6/21/18 3:24 PM, Yang Shi wrote: > > > On 6/21/18 3:10 PM, Kirill A. Shutemov wrote: >> On Fri, Jun 22, 2018 at 05:40:47AM +0800, Yang Shi wrote: >>> When merging anonymous page vma, if the size of vam can fit in at least >> s/vam/vma/ >> >>> one hugepage, the mm will be registered for khugepaged for collapsing >>> THP in the future. >>> >>> But, it skips shmem vma. Doing so for shmem too when merging vma in >>> order to increase the odd to collapse hugepage by khugepaged. >> Good catch. Thanks. >> >> I think the fix incomplete. We shouldn't require vma->anon_vma for >> shmem, >> only for anonymous mappings. We don't support file-private THPs. > > So you mean, shmem_file(vma->vm_file) && PageAnon(page)? I got your point. Please disregard the question. > >> >>> Also increase the count of shmem THP collapse. It looks missed before. >> Separate patch, please. > > Sure. > > Thanks, > Yang > >> >