Date: Fri, 6 May 2005 16:09:52 -0700 From: Kris Kennaway <kris@obsecurity.org> To: ticso@cicely.de Cc: Kris Kennaway <kris@obsecurity.org> Subject: Re: Benchmarking mpsafevfs with parallel tarball extraction Message-ID: <20050506230952.GB35398@xor.obsecurity.org> In-Reply-To: <20050506225926.GB75629@cicely12.cicely.de> References: <20050506183529.GA46411@xor.obsecurity.org> <20050506184852.GA62656@xor.obsecurity.org> <20050506200635.GB79102@xor.obsecurity.org> <20050506225926.GB75629@cicely12.cicely.de>
index | next in thread | previous in thread | raw e-mail
[-- Attachment #1 --] On Sat, May 07, 2005 at 12:59:27AM +0200, Bernd Walter wrote: > 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. 1M block size, not 1K :) Kris [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFCe/k/Wry0BWjoQKURAnlpAJ0Ycwo3z9S2edq0eCOqQVDnyTjmDgCgsd7S oLEFW1ev3yYw79F23PP1evw= =sap7 -----END PGP SIGNATURE-----help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050506230952.GB35398>