Date: Fri, 07 Jul 2000 14:16:18 -0600 From: Chuck Paterson <cp@bsdi.com> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Alfred Perlstein <bright@wintelcom.net>, Marius Bendiksen <mbendiks@eunet.no>, Bill Fumerola <billf@chimesnet.com>, freebsd-arch@freebsd.org Subject: Re: Alterations to vops Message-ID: <200007072016.OAA16071@berserker.bsdi.com>
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Matthew Dillon wrote on: Fri, 07 Jul 2000 12:50:11 PDT } } Programs such as cvsup and find do not queue up billions of } I/O's. They queue up one at a time pretty much, but the I/O's } generate a lot of seeking due to the directory layouts on the } media (when you have lots of small directories). } } -Matt } Matthew Dillon } <dillon@backplane.com> } } If for whatever reason part of your vm working gets paged out or has to be repaged in from an executable the system can have really bad user response. As Matt points out there aren't bunches of I/O queued from these processes, but you are still screwed. The process you are interested in gets to do one paging operation and then all other processes get to do one of there I/O operations. If there are a couple of processes running in the background then the disk ends up doing several seeks for every page your interactive process needs filled. Chuck To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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