Date: Mon, 12 Mar 2001 22:20:32 +0100 (CET) From: Soren Schmidt <sos@freebsd.dk> To: bright@wintelcom.net (Alfred Perlstein) Cc: oberman@es.net (Kevin Oberman), mobile@FreeBSD.ORG, stable@FreeBSD.ORG Subject: Re: Disk I/O problem in 4.3-BETA Message-ID: <200103122120.WAA10675@freebsd.dk> In-Reply-To: <20010312125905.X18351@fw.wintelcom.net> from Alfred Perlstein at "Mar 12, 2001 12:59:05 pm"
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It seems Alfred Perlstein wrote: > > > Prior to March 1 I could dd a 4 GB slice in 580 seconds (or a bit > > > under 10 minutes). After March 1 the same exact command took just > > > under 40 minutes to complete. The same was seen copying a 2 GB > > > slice. It increased from 5 minutes to 20 minutes. No kernel > > > configuration changes were made. > > > > This is worse than expected, try to use option ATA_ENABLE_WC > > and see what gives, if its not back to normal we have to look elsewhere. > > Mr ATA, is there no ATA command to "syncronize cache" like in SCSI? Yes, there is, and the ATA driver even uses it, the problem is WHEN to use it. I originally made it flush the cache if a write contained the BIO_ORDERED bit, but that doesn't work with softupdates.. If somebody can come up with a way to tell me when I need to flush the write cache, then I'll happily add that.. -Søren To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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