[En-Nut-Discussion] Improvement for faster mounting of

Rob van Lieshout (PragmaLab) info at pragmalab.nl
Thu Jan 21 08:55:03 CET 2010

> An optimization that may be put into Nut/OS could be to control the
> free
> cluster counting via ioctl(). If we could implement a control that
> configures for counting clusters or not before mounting would be a nice
> idea.
> That would improve speed for all using the card for read only.
> Then we should try an improvement for those who need to write a card.
> I don't see that counting free clusters in background is an
> improvement, as
> one needs to wait for that information before writing, regardless if
> it's
> calculated in your task or in a parallel one.
> Best regards, Ulrich

Hello Ulrich,

Good proposal. This way we provide a flexible way to determine the moment to
count the clusters, while still honoring the module and driver structure.
Counting in a background task can be implemented using this ioctl() function
if you would like the idea of a background task. I suppose your application
will be leading in whether you counting in the background will help you or
not, it's not a general rule. If the application starts writing right after
mounting, a background task will not speed up things. If writing starts
hours after mounting (like in our case), the counting is done when you need
the result.

Best regards,


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