Messages in this thread | | | Date | Wed, 28 Feb 2001 06:04:12 +0100 (CET) | From | Mike Galbraith <> | Subject | Re: [patch][rfc][rft] vm throughput 2.4.2-ac4 |
| |
On Tue, 27 Feb 2001, Marcelo Tosatti wrote:
> On Tue, 27 Feb 2001, Mike Galbraith wrote: > > > What the patch does is simply to push I/O as fast as we can.. we're > > by definition I/O bound and _can't_ defer it under any circumstance, > > for in this direction lies constipation. The only thing in the world > > which will make it better is pushing I/O. > > In your I/O bound case, yes. But not in all cases.
That's one reason I tossed it out. I don't _think_ it should have any negative effect on other loads, but a test run might find otherwise.
> > What we do right now (as kswapd) is scan a tiny portion of the active > > page list, and then push an arbitrary amount of swap because we can't > > possibly deactivate enough pages if our shortage is larger than the > > search area (nr_active_pages >> 6).. repeat until give-up time. In > > practice here (test load, but still..), that leads to pushing soon > > to be unneeded [supposition!] pages into swap a full 3/4 of the time.
(correction: it's 2/3 of the time not 3/4.. off by one bug in fingers;)
> Have you tried to use SWAP_SHIFT as 4 instead of 5 on a stock 2.4.2-ac5 to > see if the system still swaps out too much?
Not yet, but will do.
-Mike
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |