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Date: Sat, 1 Jun 1996 22:43:46 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199606011243.WAA17058@godzilla.zeta.org.au>
To: dufault@hda, terry@lambert.org
Subject: Re: Breaking ffs - speed enhancement?
Cc: hackers@FreeBSD.ORG
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>Even with _POSIX_SYNCHRONOUS_IO and nothing opened *SYNC (that is,
>you can be as aggressive as you are clever), POSIX requires that
>the file access times be updated when a "stat" or "fstat" happens
>and when no process has the file open. This precludes a standard
>way of efficiently handling files that are being rapidly opened
>and closed where you don't care about the access times.  I think
>they should have changed this part of the spec when they defined
>the sychronous I/O to let you only update the access fields when
>the associated I/O takes place, permitting standard "aggressively
>asynchronous" behavior.

It already permits agressive async behaviour, because update has
nothing to do with writing to disk.  It just requires the update
marks (if any) to be converted to actual timestamps.

Bruce