Subject: swap device, pageout on pmax broken?
To: None <jonathan@dsg.stanford.edu>
From: Gordon W. Ross <gwr@mc.com>
List: tech-kern
Date: 08/02/1995 12:56:17
> Date: Wed, 2 Aug 1995 03:37:20 -0700
> From: Jonathan Stone <jonathan@dsg.stanford.edu>
> pefo@enea.se (Per Fogelstrom) writes:
> >And will not work before the line
> > dev_t swapdev = makedev(1, 0);
> >in conf.c is fixed so it points at the swap pseudo device instead
> >of a dummy (nodev).
>
> Pageout seems to be thoroughly broken on pmaxes. The cdevsw says:
>
> struct cdevsw cdevsw[] =
> {
> cdev_cn_init(1,cn), /* 0: virtual console */
> cdev_swap_init(1,sw), /* 1: /dev/drum (swap pseudo-device) */
>
> /* ... */
> }
>
> so makedev(1, 0) isn't _entirely_ wrong.
>
> Is swapdev meant to be the *block* device or the *raw* device?
The variable swapdev is the block device for swap.
> Do they have to be the same major number for the swap device?
No, they can be different. Sun3 has swap_bmaj=4, swap_cmaj=7
Note that by contrast, the function iskmemdev() gets a chr device.
Gordon