Sysinstall automatic filesystem size generation.
Don Lewis
truckman at FreeBSD.org
Tue Aug 30 03:36:52 GMT 2005
On 29 Aug, Jon Dama wrote:
> It seems you need to add a layer of indirection. (owing to biodone being
> called merely when the drive has cached the request). What you know is
> that those operations marked completed by biodone are in fact done only
> after a (costly) flush cache operation is executed.
>
> Therefore you want to delay this operation for as long as possible, in
> fact until you actually depend on biodone being honest. I.e., at the time
> another operation is inserted into the WORKLIST.
>
> The secret I think is to keep track of which bp's marked B_DONE by
> biodone that have been certified by a flush cache. Thus permitting you to
> avoid some cache flushes. Furthermore, the softdep code has to be
> responsible for envoking the flush cache operation when it notices that
> the B_DONE flag that it cares about does not have a matching
> B_REALLY_DONE flag, which every block should have that had B_DONE set
> before the flush cache operation happened.
I believe you are correct.
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