Re: Benchmarking mpsafevfs with parallel tarball extraction

On Fri, May 06, 2005 at 01:06:35PM -0700, Kris Kennaway wrote:
> On Fri, May 06, 2005 at 11:48:52AM -0700, Kris Kennaway wrote:
> > On Fri, May 06, 2005 at 11:35:29AM -0700, Kris Kennaway wrote:
> > 
> > > I might be bumping into the bandwidth of md here - when I ran less
> > > rigorous tests with lower concurrency of extractions I seemed to be
> > > getting marginally better performance (about an effective concurrency
> > > of 2.2 for both 3 and 10 simultaneous extractions - so at least it
> > > doesn't seem to degrade badly).  Or this might be reflecting VFS lock
> > > contention (which there is certainly a lot of, according to mutex
> > > profiling traces).
> > 
> > I suspect that I am hitting the md bandwidth:
> > 
> > # dd if=/dev/zero of=/dev/md0 bs=1024k count=500
> > 500+0 records in
> > 500+0 records out
> > 524288000 bytes transferred in 9.501760 secs (55177988 bytes/sec)

Wasn't md's blocksize = systems's pagesize, IIRC 8k on sparc.
I'm surprised that 1k even works.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd@bwct.de                                  info@bwct.de

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