On Fri, Jul 29, 2011 at 11:58 PM, Ted Unangst <[email protected]> wrote: > On Fri, Jul 29, 2011, Mattieu Baptiste wrote: > >> After digging around this problem with help from Pedro, I noticed that >> a 4.9-release kernel works ok, whereas a 5.0-beta does not. So I tried >> to identify which commit was responsible and found out this one is >> responsible of *very* slow writes with softdep (I only have this bug >> on sparc64): >> http://marc.info/?l=openbsd-cvs&m=130730313107059&w=2 >> >> I can add that this bug is just affecting softdep: >> - dd'ing to the raw device is fast, >> - dd'ing to the file system mounted sync is very fast, >> - dd'ing to the file system mounted async is very fast, >> - dd'ing to the file system mounted with softdep is very slow. >> >> I can also add that changing a working kernel to bufcachepercent >=42 >> via sysctl is ok too. > > What happens if you change bufcachepercent to a much smaller value, like > the 4.9 default?
If I change kern.bufcachepercent via sysctl to 10 or 5, it's still very slow. -- Mattieu Baptiste "/earth is 102% full ... please delete anyone you can."
