Re: 2.2.0-pre[56] swap performance poor with > 1 thrashing task

Andrea Arcangeli
1999-01-16T20:37:24Z

On Fri, 8 Jan 1999, Linus Torvalds wrote:

> As a no-op, it can now randomly and unprectably result in even worthwhile
> buffers just being thrown out - possibly quite soon after they've been
> loaded in. I happen to believe that it doesn't actually matter (and I'm

I think it doesn't matter because the buffer_under_min() check just
protect the buffer cache enough. In arca-vm-22 I removed the specific
buffer and cache min limitis so I applyed Zlatko patch ;).

Basically arca-vm-22 take the sum of the buffermem+page_cache_size always
close to a percentage tunable via sysctl (10% as default) when _low_ on
memory. So the buffer aging now make sense to me (not benchmarked though
;).

Somebody in the list asked for an algorithm that doens't work with magic
but it's tunable. Having a constant cache+buffermem memory size under
swapping seems to work very well and even if it doesn't work with magic I
like it right now.

Andrea Arcangeli