[9fans] Swap considered harmful (Sorry)

[Brantley Coile <brantley@coraid.com>]

char Ephil[] = "It's all Phil's fault";


> From: "rob pike" <;rob@plan9.bell-labs.com>;
> Subject: Re: [9fans] Virtual memory in BSD and Plan9
> Date: Mon, 29 Oct 2001 07:38:17 -0500
>
> I'm a radical here, but I think if a machine is paging, you've lost.
> To me, VM is a pretty technique for memory management in the kernel,
> something distinct from paging, which is a way to get the system
> through temprorary overshoots in memory demand.
>
> My boss when the first Plan 9 kernel was being written was Sandy
> Fraser, who had worked on Atlas, one of the first VM systems.  When he
> heard that I was putting VM into Plan 9 (a situation more accurately
> described as building Plan 9's original memory manager around a VM
> model), he literally called me on the carpet.  He said that he hated
> VM bitterly because of the Atlas days, in which nothing got done
> because the system was always thrashing.  I pointed out the
> distinction between VM and paging, explained that I was implementing
> VM but not paging (Phil W. put paging in a few years later), and
> justified my decision by pointing out that with memory so cheap today,
> there was really no reason to depend on the paging system to manage
> your working set except for the occasional brief overrun on demand.
>
> -rob