DragonFly kernel List (threaded) for 2008-05
Re: Blogbench results for HAMMER
Matthew Dillon wrote:
> I ran blockbench on a HAMMER partition and on a UFS partition and
> got some rather interesting results.
> I fully expected HAMMER's write performance to be bad compared to
> because HAMMER is still double-buffering its data. Indeed, as the
> test began UFS seemed to be outdoing HAMMER. But as the number
> grew and the kernel started to have to recycle vnodes and
> performance went completely to hell while HAMMER was able to
> throughput. Ths basic blog benchmark creates, reads, and writes
> 20,000 files and goes for a lot of parallelism.
> I don't know why UFS's write performance went to hell.. it pretty
> died completely after a very promising start. But even ignoring that
> as some sort of implementation fluke the read performance numbers
> for themselves.
> I haven't run bonnie++ yet. I think UFS still does very well vs
> on saturated single-file I/O.
Would be nice to see some UFS benchmarks of FreeBSD, to make sure it's
not an issue with DragonFly's UFS "implementation". Too sad that I don't
have UFS anymore (only ZFS), so I could do it myself. And then, the
benchmark should be done on one and the same machine. But probably it's
wise to wait a few days for benchmarks :)