On Tue, May 19 2020 at 4:14am -0400, Hannes Reinecke <hare@xxxxxxx> wrote: > Hi all, > > here's an update to dm-zoned to separate out cache zones. > In the update to metadata version 2 the regular drive was split > in emulated zones, which were handled just like 'normal' random > write zones. > This causes a performance drop once these emulated zones have > been mapped, as typicall the random zones from the zoned drive > will perform noticeably slower than those from the regular drive. > (After all, that was kinda the idea of using a regular disk in > the first place ...) > > So in this patchset I've introduced a separate 'cache' zone type, > allowing us to differentiate between emulated and real zones. > With that we can switch the allocation mode to use only cache > zones, and use random zones similar to sequential write zones. > That avoids the performance issue noted above. > > I've also found that the sequential write zones perform noticeably > better on writes (which is all we're caching anyway), so I've > added another patch switching the allocation routine from preferring > sequential write zones for reclaim. > > This patchset also contains some minor fixes like remving an unused > variable etc. > > As usual, comments and reviews are welcome. > > Changes to v1: > - Include reviews from Damien I'll take a look at this series now, but I'm still waiting for formal Reviewed-by: or Acked-by: from Damien before I'll stage for 5.8 -- current development window is coming to a close though. > - Introduce allocation flags > - Terminate reclaim on contention > - Rework original patch series > > Hannes Reinecke (6): > dm-zoned: return NULL if dmz_get_zone_for_reclaim() fails to find a zone > dm-zoned: separate random and cache zones > dm-zoned: reclaim random zones when idle > dm-zoned: start reclaim with sequential zones > dm-zoned: terminate reclaim on congestion > dm-zoned: remove unused variable in dmz_do_reclaim() FYI I folded the last 6/6 patch back into the original commit that introduced the unused variable (via rebase). Thanks, Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
