From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754198AbcHaVgO (ORCPT ); Wed, 31 Aug 2016 17:36:14 -0400 Received: from mga04.intel.com ([192.55.52.120]:64225 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753708AbcHaVgM (ORCPT ); Wed, 31 Aug 2016 17:36:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,263,1470726000"; d="scan'208";a="1049846289" Date: Wed, 31 Aug 2016 15:36:07 -0600 From: Ross Zwisler To: "Kani, Toshimitsu" Cc: "ross.zwisler@linux.intel.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "adilger.kernel@dilger.ca" , "viro@zeniv.linux.org.uk" , "dan.j.williams@intel.com" , "akpm@linux-foundation.org" , "mawilcox@microsoft.com" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" , "jack@suse.com" , "tytso@mit.edu" , "linux-ext4@vger.kernel.org" , "david@fromorbit.com" Subject: Re: [PATCH v2 0/9] re-enable DAX PMD support Message-ID: <20160831213607.GA6921@linux.intel.com> Mail-Followup-To: Ross Zwisler , "Kani, Toshimitsu" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "adilger.kernel@dilger.ca" , "viro@zeniv.linux.org.uk" , "dan.j.williams@intel.com" , "akpm@linux-foundation.org" , "mawilcox@microsoft.com" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" , "jack@suse.com" , "tytso@mit.edu" , "linux-ext4@vger.kernel.org" , "david@fromorbit.com" References: <20160823220419.11717-1-ross.zwisler@linux.intel.com> <20160830230150.GA12173@linux.intel.com> <1472674799.2092.19.camel@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1472674799.2092.19.camel@hpe.com> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2016 at 08:20:48PM +0000, Kani, Toshimitsu wrote: > On Tue, 2016-08-30 at 17:01 -0600, Ross Zwisler wrote: > > On Tue, Aug 23, 2016 at 04:04:10PM -0600, Ross Zwisler wrote: > > > > > > DAX PMDs have been disabled since Jan Kara introduced DAX radix > > > tree based locking.  This series allows DAX PMDs to participate in > > > the DAX radix tree based locking scheme so that they can be re- > > > enabled. > > > > > > Changes since v1: > > >  - PMD entry locking is now done based on the starting offset of > > > the PMD entry, rather than on the radix tree slot which was > > > unreliable. (Jan) > > >  - Fixed the one issue I could find with hole punch.  As far as I > > > can tell hole punch now works correctly for both PMD and PTE DAX > > > entries, 4k zero pages and huge zero pages. > > >  - Fixed the way that ext2 returns the size of holes in > > > ext2_get_block(). (Jan) > > >  - Made the 'wait_table' global variable static in respnse to a > > > sparse warning. > > >  - Fixed some more inconsitent usage between the names 'ret' and > > > 'entry' for radix tree entry variables. > > > > > > Ross Zwisler (9): > > >   ext4: allow DAX writeback for hole punch > > >   ext2: tell DAX the size of allocation holes > > >   ext4: tell DAX the size of allocation holes > > >   dax: remove buffer_size_valid() > > >   dax: make 'wait_table' global variable static > > >   dax: consistent variable naming for DAX entries > > >   dax: coordinate locking for offsets in PMD range > > >   dax: re-enable DAX PMD support > > >   dax: remove "depends on BROKEN" from FS_DAX_PMD > > > > > >  fs/Kconfig          |   1 - > > >  fs/dax.c            | 297 +++++++++++++++++++++++++++++----------- > > > ------------ > > >  fs/ext2/inode.c     |   3 + > > >  fs/ext4/inode.c     |   7 +- > > >  include/linux/dax.h |  29 ++++- > > >  mm/filemap.c        |   6 +- > > >  6 files changed, 201 insertions(+), 142 deletions(-) > > > > > > --  > > > 2.9.0 > > > > Ping on this series?  Any objections or comments? > > Hi Ross, > > I am seeing a major performance loss in fio mmap test with this patch- > set applied.  This happens with or without my patches [1] applied on > top of yours.  Without my patches, dax_pmd_fault() falls back to the > pte handler since an mmap'ed address is not 2MB-aligned. > > I have attached three test results. >  o rc4.log - 4.8.0-rc4 (base) >  o non-pmd.log - 4.8.0-rc4 + your patchset (fall back to pte) >  o pmd.log - 4.8.0-rc4 + your patchset + my patchset (use pmd maps) > > My test steps are as follows. > > mkfs.ext4 -O bigalloc -C 2M /dev/pmem0 > mount -o dax /dev/pmem0 /mnt/pmem0 > numactl --preferred block:pmem0 --cpunodebind block:pmem0 fio test.fio > > "test.fio" > --- > [global] > bs=4k > size=2G > directory=/mnt/pmem0 > ioengine=mmap > [randrw] > rw=randrw > --- > > Can you please take a look? Yep, thanks for the report.