On 7/15/19 9:22 PM, Mike Snitzer wrote: > On Fri, Jul 12 2019 at 9:45am -0400, > Nikos Tsironis <ntsironis@xxxxxxxxxxx> wrote: > >> Hi Mike, >> >> A kind reminder about this patch. Do you require any changes or will you >> merge it as is? > > I think we need changes to expose knob(s) to tune this value on a global > _and_ device level via sysfs. E.g.: > > 1) dm_mod module param for global > 2) but also allow a per-device override, like: > echo 512 > /sys/block/dm-X/dm/kcopyd_subjob_size > Hi Mike, Thanks for your feedback. I agree, this sounds like the best thing to do. > 1 is super easy and is a start. Layering in 2 is a bit more involved. Maybe I could help with (2). We could discuss about it and how you think it's best to do it and then I could proceed with an implementation. Please let me know what you think. > > In hindsight (given how risk-averse I am on changing the default) I > should've kept the default 128 but allowed override with modparam > dm_mod.kcopyd_subjob_size=1024 > > Would this be an OK first step? Yes, this would be great. > > If so, we're still in the 5.3 merge window, I'll see what I can do. Shall I proceed with a patch adding the dm_mod.kcopyd_subjob_size modparam? Thanks, Nikos > > Thanks, > Mike > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
