Re: [patch for playing] Patch to support 4000 disks and maintain backward compatibility

[James Bottomley <James.Bottomley@steeleye.com>]

On Fri, 2003-04-11 at 06:42, Andries.Brouwer@cwi.nl wrote:
>     Here is my problem..
> 
>     #insmod ips.o
>       < found 10 disks>
>     #insmod qla2300.o
>       < found 10 disks>
>     #rmmod ips.o
>        <removed 10 disks>
>     #insmod ips.o
>       <found 10 disks - but new names>
> 
> OK, I see what you mean. I agree.

Could you elaborate on the reason you want to keep the minor space
compact?  I don't regard the insmod/rmmod problem as valid because if
you do:

rmmod ips.o
rmmod qla2300.o
insmod qla2300.o
insmod ips.o

All bets are off again. For small kernel dev_t it was essential to keep
a compact minor space because otherwise we coulde run out of minors. 
Sparse minors cause no inefficiency in the mid-layer, or in sd.  There
are problems in sg which could be solved by encoding the device type in
the minor.

> [I see that dougg wants to solve such things by properly naming,
> but that is a higher level. Given a large number space an
> easier solution is to give each module its own part of the
> number space.]

Please, no.  Dividing up the minor space like this would be a step
backwards (adding more policy to the kernel).  Someone would also have
to manage this scheme.

James