Re: why umsdos?

Riley Williams (rhw@bigfoot.com)
Mon, 9 Nov 1998 10:55:24 +0000 (GMT)


Hi Anthony.

>>> 2. No speed improvement, most likely there would be a speed
>>> decrease.

>>> file system request -> UMSDOS -> FATFS -> drive

>>> vs.

>>> file system request -> EXT2 -> loop device driver ->
>>> FATFS -> drive

>> Show me the numbers, I'm not convinced.

> You're adding another layer to the I/O flow and you expect a speed
> up???

In my experience, EXT2 + the lop device driver combined ARE faster
than the current UMSDOS layer, so there would be a definate speed
increase from making that change...

My analysis indicates that the really slow section of the UMSDOS
driver is its filename translation routine, although I'm not sure why.
That's why I suggested using VFAT as the underlying file system rather
than MSDOS - it eliminates that routine completely since VFAT can
already handle long filenames, so doesn't need it.

Best wishes from Riley.

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