On Wed, Feb 19, 2020 at 09:09:45AM -0800, Darrick J. Wong wrote: > On Wed, Feb 19, 2020 at 02:38:24PM +0000, Luis Chamberlain wrote: > > On Wed, Feb 19, 2020 at 03:32:27PM +0100, Carlos Maiolino wrote: > > > On Wed, Feb 19, 2020 at 01:57:15PM +0000, Luis Chamberlain wrote: > > > > I hear some folks still use CONFIG_XFS_RT, I was curious what was the > > > > actual modern typical use case for it. I thought this was somewhat > > > > realted to DAX use but upon a quick code inspection I see direct > > > > realtionship. > > > > > > Hm, not sure if there is any other use other than it's original purpose of > > > reducing latency jitters. Also XFS_RT dates way back from the day DAX was even a > > > thing. But anyway, I don't have much experience using XFS_RT by myself, and I > > > probably raised more questions than answers to yours :P > > > > What about another question, this would certainly drive the users out of > > the corners: can we remove it upstream? > > My DVR and TV still use it to record video data. Is anyone productizing on that though? I was curious since most distros are disabling CONFIG_XFS_RT so I was curious who was actually testing this stuff or caring about it. > I've also been pushing the realtime volume for persistent memory devices > because you can guarantee that all the expensive pmem gets used for data > storage, that the extents will always be perfectly aligned to large page > sizes, and that fs metadata will never defeat that alignment guarantee. For those that *are* using XFS in production with realtime volume with dax... I wonder whatcha doing about all these tests on fstests which we don't have a proper way to know if the test succeeded / failed [0] when an external logdev is used, this then applies to regular external log dev users as well [1]. Which makes me also wonder then, what are the typical big users of the regular external log device? Reviewing a way to address this on fstests has been on my TODO for a while, but it begs the question of how much do we really care first. And that's what I was really trying to figure out. Can / should we phase out external logdev / realtime dev? Who really is caring about this code these days? [0] https://github.com/mcgrof/oscheck/blob/master/expunges/linux-next-xfs/xfs/unassigned/xfs_realtimedev.txt [1] https://github.com/mcgrof/oscheck/blob/master/expunges/linux-next-xfs/xfs/unassigned/xfs_logdev.txt Luis
