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SubjectRe: disk head scheduling
Date
From
Linus Torvalds wrote:
>
>
> On Mon, 22 Mar 1999, Rogier Wolff wrote:
> >
> > To save on the (indirect) function call, I would like to suggest:
> >
> > unsigned char **queue_numbers;
> >
> > queue_number = queue_numbers[major][minor];
>
> This is what we do for block sizes, and it's a complete horror to maintain
> and debug. Even worse: it forces us to have 8-bit minor and major numbers
> forever.

Nah! It is the device drivers responsibility to allocate enough
space. So if a new SCSI disk driver notices 20 disks, and therefore
wants 320 minors, it should allocate the array to be 320 entries.

But indeed as soon as the 8bit restriction on minors is lifted, nobody
will allocate the minors close together anymore, leading to sparsely
used arrays.

Roger.

--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
------ Microsoft gives you Windows, Linux gives you the whole house ------


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