Subject: Re: netbsd-4: processes looping in "lfsresbuf"
To: None <firstname.lastname@example.org,>
From: Blair Sadewitz <email@example.com>
Date: 09/28/2007 14:58:35
90% is about where I'd expect problems to start happening with our
current implementation. Performance at close to capacity is a
weakness of LFS in general, AFAIK.
Moreover, LFS is unfortunately not always stable on -current (in the
MP case). Also, IIRC, lfsresbuf is one place with a [possibly]
problematic call to ltsleep(). I've done some testing using
decreasing values of vfs.lfs.pagetrip on -current, and notice that
locking problems manifest more and more the smaller the "page trip"
gets, increasing geometrically after it's lowered below
segsize/PAGE_SIZE. In your case, mega-maid, e.g. the cleaner, acting
up may also be an issue.
If you use ffs+softdep and raise kern.maxvnodes, you likely will get
the better performance writing tons of small files that you're looking