From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 7281A82F64 for ; Wed, 31 Aug 2016 17:36:10 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id g202so11791980pfb.3 for ; Wed, 31 Aug 2016 14:36:10 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id b64si1687753pfa.51.2016.08.31.14.36.09 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 31 Aug 2016 14:36:09 -0700 (PDT) Date: Wed, 31 Aug 2016 15:36:07 -0600 From: Ross Zwisler Subject: Re: [PATCH v2 0/9] re-enable DAX PMD support Message-ID: <20160831213607.GA6921@linux.intel.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> Sender: owner-linux-mm@kvack.org List-ID: 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" 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. -- 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