From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) by kanga.kvack.org (Postfix) with ESMTP id 997B06B006E for ; Mon, 30 Mar 2015 11:40:50 -0400 (EDT) Received: by pdnc3 with SMTP id c3so179427537pdn.0 for ; Mon, 30 Mar 2015 08:40:50 -0700 (PDT) Received: from e28smtp09.in.ibm.com (e28smtp09.in.ibm.com. [122.248.162.9]) by mx.google.com with ESMTPS id jc8si15266398pbd.25.2015.03.30.08.40.47 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 30 Mar 2015 08:40:49 -0700 (PDT) Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 30 Mar 2015 21:10:45 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id BF1F0E0045 for ; Mon, 30 Mar 2015 21:13:00 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2UFeguh43974742 for ; Mon, 30 Mar 2015 21:10:42 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2UFTYuB032437 for ; Mon, 30 Mar 2015 20:59:35 +0530 From: "Aneesh Kumar K.V" Subject: Re: [PATCHv4 00/24] THP refcounting redesign In-Reply-To: <1425486792-93161-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1425486792-93161-1-git-send-email-kirill.shutemov@linux.intel.com> Date: Mon, 30 Mar 2015 21:10:41 +0530 Message-ID: <87ego6lchy.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli Cc: Dave Hansen , Hugh Dickins , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , Johannes Weiner , Michal Hocko , Jerome Marchand , linux-kernel@vger.kernel.org, linux-mm@kvack.org "Kirill A. Shutemov" writes: > Hello everybody, > > It's bug-fix update of my thp refcounting work. > > The goal of patchset is to make refcounting on THP pages cheaper with > simpler semantics and allow the same THP compound page to be mapped with > PMD and PTEs. This is required to get reasonable THP-pagecache > implementation. > > With the new refcounting design it's much easier to protect against > split_huge_page(): simple reference on a page will make you the deal. > It makes gup_fast() implementation simpler and doesn't require > special-case in futex code to handle tail THP pages. > > It should improve THP utilization over the system since splitting THP in > one process doesn't necessary lead to splitting the page in all other > processes have the page mapped. Can we split this series into two. The compound_lock removal and using migration entries ro freeze page count can be made into a seperate series ? -aneesh -- 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