Date: Mon, 10 Feb 2003 10:34:39 +1030 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: arch@freebsd.org Subject: Re: Our lemming-syncer caught in the act. Message-ID: <20030210000439.GG60203@wantadilla.lemis.com> In-Reply-To: <31118.1044817404@critter.freebsd.dk> References: <31118.1044817404@critter.freebsd.dk>
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--2E/hm+v6kSLEYT3h Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sunday, 9 February 2003 at 20:03:24 +0100, Poul-Henning Kamp wrote: > > I have suspected our syncer of being subobtimal for some time, based > simply on my perception of the disk-light on my laptop and the > dynamics of the "dirty" counter in systat. > > I played with the new GEOM I/O statistics stuff and guess what: I > caught it in the act: > > http://phk.freebsd.dk/misc/disk.png > > Green is the number of unfinished requests. > > Most of the red "impulse" represents one request finishing after > as many milliseconds as it is tall. The remainder of the impulses > cover more than one request, the height is then the average of the > time it has taken to service them. > > An image is worth a thousand words, but in this case it only > says three words: "Man, that sucks!". Nope, it's one of the prettiest graphs I've seen in a long time. Greg -- See complete headers for address and phone numbers --2E/hm+v6kSLEYT3h Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.0 (FreeBSD) iD8DBQE+RuyWIubykFB6QiMRAlhlAKCw8KJW6qTbTSI4GpVXcM4s67ODhQCeMx2a n4sCUUYSZLW0Xh1hA3EcgFY= =uXuQ -----END PGP SIGNATURE----- --2E/hm+v6kSLEYT3h-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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