From owner-freebsd-arch Sun Feb 9 16: 4:44 2003 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5091337B401 for ; Sun, 9 Feb 2003 16:04:42 -0800 (PST) Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id D093843FA3 for ; Sun, 9 Feb 2003 16:04:40 -0800 (PST) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 188C251978; Mon, 10 Feb 2003 10:34:39 +1030 (CST) Date: Mon, 10 Feb 2003 10:34:39 +1030 From: Greg 'groggy' Lehey To: Poul-Henning Kamp Cc: arch@freebsd.org Subject: Re: Our lemming-syncer caught in the act. Message-ID: <20030210000439.GG60203@wantadilla.lemis.com> References: <31118.1044817404@critter.freebsd.dk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2E/hm+v6kSLEYT3h" Content-Disposition: inline In-Reply-To: <31118.1044817404@critter.freebsd.dk> User-Agent: Mutt/1.4i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG --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