On Sun, 2011-06-19 at 02:48 +0100, Alasdair G Kergon wrote: > All I can suggest is studying the existing upstream targets to > understand better how they work and perhaps avoid problems like the ones > you are seeing. How about DM_MAPIO_REQUEUE ? > > What is your target trying to do? it is just a simple model target now which passes back requests from inbox queue to dm_io() on a single backend dev in context of target's work queue. > (Why is split_io important? well, for same reason like dm-stripe. i may need this in the future for switching backend devices dynamically according to bio LBA. This is why i want to have a bio of size not bigger than split_io. > Did you implement a merge fn?) no, i didn't. i don't know a purpose of merge fn. I can see that e.g. dm-stripe doesn't use this callback in 2.6.33 kernel while dm-stripe from 2.6.39 uses it. furthermore dm-linear from 2.6.33 and .39 utilize .merge but split_io is 0. > > Alasdair > -- Krzysztof Blaszkowski -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
