Naohiro Aota - 07.02.20, 07:06:00 CET: > On Thu, Feb 06, 2020 at 12:43:30PM +0100, Martin Steigerwald wrote: > >Hi Naohiro. > > > >Naohiro Aota - 06.02.20, 11:41:54 CET: > >> This series refactors chunk allocation, device_extent allocation > >> and > >> extent allocation functions and make them generalized to be able to > >> implement other allocation policy easily. > >> > >> On top of this series, we can simplify some part of the "btrfs: > >> zoned > >> block device support" series as adding a new type of chunk > >> allocator > >> and extent allocator for zoned block devices. Furthermore, we will > >> be > >> able to implement and test some other allocator in the idea page of > >> the wiki e.g. SSD caching, dedicated metadata drive, chunk > >> allocation > >> groups, and so on. > > > >Regarding SSD caching, are you aware that there has been previous > >work with even involved handling part of it in the Virtual > >Filesystem Switch (VFS)? > > > >VFS hot-data tracking, LWN article: > > > >https://lwn.net/Articles/525651/ > > > >Patchset, not sure whether it is the most recent one: > > > >[PATCH v2 00/12] VFS hot tracking > > > >https://lore.kernel.org/linux-btrfs/1368493184-5939-1-git-send-email-> >zwu.kernel@xxxxxxxxx/ > Yes, I once saw the patchset. Not sure about the detail, though. > > >So for SSD caching you may be able to re-use or pick up some of this > >work, unless it would be unsuitable to be used with this new > >approach. > Currently, I have no plan to implement the SSD caching feature by > myself. I think some patches of the series like this [1] can be > reworked on my series as adding an "SSD caching chunk allocator." So, > it's welcome to hear suggestions about the hook interface. Thank you. Adding Zhi Yong Wu to Cc. I don't know details about this patch set either. @Zhi Yong Wu: Are you interested interested in rebasing your SSD caching patch above this refactoring work? Ciao, Martin > [1] > https://lore.kernel.org/linux-btrfs/1371817260-8615-3-git-send-email-> zwu.kernel@xxxxxxxxx/ > >Thanks, -- Martin
