Date: Fri, 01 Jun 2001 18:04:35 -0700 From: Peter Wemm <peter@wemm.org> To: tlambert2@mindspring.com Cc: Mike Silbersack <silby@silby.com>, Terry Lambert <tlambert@primenet.com>, hackers@FreeBSD.ORG Subject: Re: general speed differences between 4.1.1-RELEASE and 4.3-RELEASE Message-ID: <20010602010435.3D04D380C@overcee.netplex.com.au> In-Reply-To: <3B17CDA4.8AADBD1@mindspring.com>
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Terry Lambert wrote: > Peter Wemm wrote: > > Terry Lambert wrote: > > > Mike Silbersack wrote: > > > > 1. Have the ata driver leave the write cache setting > > > > alone by default, providing a sysctl which can cause > > > > disabled or enabled if requested. When the default is > > > > allowed, put something in dmesg which says "Note: Write > > > > caching may be enabled. See ata(4) for the reliability > > > > implications of this." > > > > > > You need to look at the code; it would be relatively hard > > > to make this runtime tunable instead of boot-time tunable. > > > > False. It is actually very easy to change at runtime if it > > is done at a convenient time. We have had patches kicking > > around for something like 6 months now that do this. > > The patches don't (and possibly can't) do enough to ensure > a smooth transition. Among other things, they would have > to turn off soft updates. No, I was talking about turning on/off write caching at the drive. Doing that is simple. If you choose to leave softupdates on, that is your problem. It doesn't have anything to do with the difficulty or not of changing the drive mode. > Please see my other post on this subject. > > -- Terry > > Cheers, -Peter -- Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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