On Aug 26, 2007, at 10:11 AM, der Mouse wrote:

> In <sys/disk.h>, I note
>
>        /*
>         * Disk label information.  Storage for the in-core disk label
>         * must be dynamically allocated, otherwise the size of this
>         * structure becomes machine-dependent.
>         */
>
> This implies that someone thought the size of the structure was MI.
> But this is false; it includes at least a handful of pointers, and  
> thus
> changes size depending on the arch's pointer size.

Machine-dependent, not architecture-dependent.

I.e. the size of that structure is the same on all m68k platforms.

> There also is no indication what would be wrong with struct disk
> changing size depending on the MD things.
>
> ISTM the comment, at least, needs updating.  Agree?  Disagree?  Anyone
> know why having struct disk's size be MI was thought to be good?

Within a given architecture, it used to be required in order for the  
kmem grovelers that read it to work properly.

-- thorpej