Date: Mon, 02 Feb 2009 10:16:30 +0100 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-geom@freebsd.org Subject: Re: Performance numbers? Message-ID: <gm6dlq$lcj$1@ger.gmane.org> In-Reply-To: <9C533E30-BD08-4938-8D1A-5CE046FB6BF6@freebsd.org> References: <6612C205-C346-4493-9DA4-3B5A73E9A4F7@freebsd.org> <glvp7l$6td$3@ger.gmane.org> <9C533E30-BD08-4938-8D1A-5CE046FB6BF6@freebsd.org>
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[-- Attachment #1 --] Eric Anderson wrote: > > On Jan 30, 2009, at 2:50 PM, Ivan Voras wrote: > >> Eric Anderson wrote: >>> Hi GEOMers! >>> >>> Does anyone have any benchmarks or numbers relating to GEOM performance? >>> >>> I tried doing some on my own, but I didn't get very satisfactory >>> results, so I'm curious what others have seen or used. >>> >>> My hardware is a Core 2 Quad, with 4GB of ram. >>> >>> First, I made an mdconfig'ed malloc backed 'disk' of 1.5GB. Then, I >>> tried running such tools as rawio, and diskinfo. rawio fails with >>> input/output errors, and diskinfo wants a larger device to give the full >>> stats. I ended up using purely dd since that worked. Interestingly >>> enough, dd'ing to the malloc device results in about 1000 operations per >>> second, regardless of a blocksize of 512bytes or 1MB. >> >> It's a good idea for testing. >> >> 1000 ops/s looks suspiciously like HZ, though I don't know why HZ would >> influence GEOM (AFAIK context switches between threads, including GEOM >> threads do not depend on it) - can you try ruling out HZ? > > Is there a way to pump the data through the GEOM layers without doing a > mdconfig'd disk? You could use gzero, it ignores written data and produces read data with memset. > Also, are you thinking setting the hz to some other setting, and > rerunning? What setting were you thinking? I can easily try anything. Yes. Try 1500. [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFJhrn1ldnAQVacBcgRAu52AKC8+YGgRqwX2VqbKBRuWkyZGyXK/gCePlbG g2btQr41+24k12240RbxxEI= =0tsg -----END PGP SIGNATURE-----
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