Date: Mon, 20 Aug 2001 12:15:11 -0400 From: Bill Moran <wmoran@iowna.com> To: Jeff Behl <jeff@expertcity.com> Cc: questions@FreeBSD.ORG Subject: Re: syncer delay? Message-ID: <3B81378F.FF4CCCD0@iowna.com> References: <3B812CA6.9060100@expertcity.com>
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Jeff Behl wrote: > > howdy, > We have a very time sensitive application that we think is being > affected by the kernel syncer process. While doing a poll call, every > 30 seconds we will have iterations that take 300+ ms longer than on average. This > only started happening after our app started needing to log data to > disk, and the delays are longer when there are more connections (more to > write/log). Would it be feasable (for your app) to call sync() after a log record is written, to be sure it cleans the cache. Perhaps during the 30 sec wait between polls you could call sync? Just a thought. > I turned on IDE write caching (hw.ata.wc) but this has had no noticeable > effect. What else can we do to try and minimize this hiccup every 30 > seconds? Is adjusting the time between sync's a worthwhile approach > (using sysctl)? We're using 4.3-RELEASE. I'm guessing that your best bet will be to try it and see if it helps. -Bill -- "Where's the robot to pat you on the back?" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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