Re: [PATCH v2 00/11] DAX fsynx/msync support
From: Jan Kara <jack@suse.cz>
Date: 2015-11-16 14:41:30
Also in:
linux-fsdevel, linux-mm, linux-xfs, lkml, nvdimm
On Fri 13-11-15 17:06:39, Ross Zwisler wrote:
This patch series adds support for fsync/msync to DAX. Patches 1 through 7 add various utilities that the DAX code will eventually need, and the DAX code itself is added by patch 8. Patches 9-11 update the three filesystems that currently support DAX, ext2, ext4 and XFS, to use the new DAX fsync/msync code. These patches build on the recent DAX locking changes from Dave Chinner, Jan Kara and myself. Dave's changes for XFS and my changes for ext2 have been merged in the v4.4 window, but Jan's are still unmerged. You can grab them here: http://www.spinics.net/lists/linux-ext4/msg49951.html
I had a quick look and the patches look sane to me. I'll try to give them more detailed look later this week. When thinking about the general design I was wondering: When we have this infrastructure to track data potentially lingering in CPU caches, would not it be a performance win to use standard cached stores in dax_io() and mark corresponding pages as dirty in page cache the same way as this patch set does it for mmaped writes? I have no idea how costly are non-temporal stores compared to cached ones and how would this compare to the cost of dirty tracking so this may be just completely bogus... Honza -- Jan Kara [off-list ref] SUSE Labs, CR -- 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>