Date: Thu, 18 Jul 2002 12:23:01 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: Ronald Klop <ronald@not4mail.cs.vu.nl> Cc: "Brian T.Schellenberger" <bts@babbleon.org>, stable@FreeBSD.ORG, Julian Elischer <julian@FreeBSD.ORG> Subject: Re: softupdates: any way to force sync? Message-ID: <Pine.BSF.4.21.0207181205540.84569-100000@InterJet.elischer.org> In-Reply-To: <3D370B42.3080504@not4mail.cs.vu.nl>
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On Thu, 18 Jul 2002, Ronald Klop wrote: > The following sysctl's define the delay before things are written to > disk with softupdates. I think they work in realtime and setting them to > 3,2,1 for a little time wil sync the disk faster. But wil make the > caching less efficient. So play with it for a while. > > kern.filedelay: 30 > kern.dirdelay: 29 > kern.metadelay: 28 Brian, When we were porting Soft Updates, Kirk suggested that a sequence of 4 syncs should be sufficient to force a full update. e.g. sync;sleep 1;sync;sleep 1;sync;sleep 1;sync I have my suspicions that it may be possible under some situations for some interdependencies to last longer, but I also am willing to believe that probably Kirk was right :-) He also said that an 'fsync()' on a file will recurse all the way to the root of the filesystem, resolving all unsatisfied dependencies on the way. You may want to consider this if you have a specific need. > > Greetings, > > Ronald. > > Brian T.Schellenberger wrote: [...] > > > > What I'd like is a command like "syncupdates" or something that would > > synchronosly force all the pending softupdates updates to update and return > > only when that was complete. Then when I had the (rare) occaisons where I > > really wanted them synced up, they could be synched up but the rest of the > > time I could still let it update when it pleased. > > > > Questions: > > > > - Is there any functionality already in the system that I don't know about? > > - Are there any plans to add it? > > - If not, I might have a go at it myself. Other than your code and the > > original paper are there any references or information that I should have in > > hand? > > - And would you, Julian, be willing to review whatever I might come up with > > and possibly commit it if it looks plausible? (I don't run current so > > whatever patches I'd come up with would be against -stable, but I presume > > that doing a sort of "reverse MFC" to translate them to -current patches > > wouldn't be terribly difficult.) > > I think there are much better people to review it than me.. I have not looked at the soft updates code for 3 years :-( Don't forget that while I commited it, I was only acting as an assitant to Kirk. I did most of the 'mecahnical' porting parts but he has moved a long way since then. (particularly in -current). To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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