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@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>