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