Messages in this thread | | | Subject | Re: [PATCH 01/16] mm: delayed page activation | From | Peter Zijlstra <> | Date | Thu, 10 Nov 2005 10:17:44 +0100 |
| |
On Wed, 2005-11-09 at 21:49 +0800, Wu Fengguang wrote: > plain text document attachment (mm-delayed-activation.patch) > When a page is referenced the second time in inactive_list, mark it with > PG_activate instead of moving it into active_list immediately. The actual > moving work is delayed to vmscan time. > > This implies two essential changes: > - keeps the adjecency of pages in lru; > - lifts the page reference counter max from 1 to 3. > > And leads to the following improvements: > - read-ahead for a leading reader will not be disturbed by a following reader; > - enables the thrashing protection logic to save pages for following readers; > - keeping relavant pages together helps improve I/O efficiency; > - and also helps decrease vm fragmantation; > - increased refcnt space might help page replacement algorithms.
I'm working on a clockpro implementation that essentialy keeps all resident pages on 1 clock. In this case readahead pages will also not fragment over the active/inactive lists but stay in order. Would that also satisfy your requirements?
Code can be found at: http://programming.kicks-ass.net/kernel-patches/clockpro-2/
Note however that this is work in progress and rather unstable, there are some livelock scenarios in there.
Kind regards,
Peter Zijlstra
- 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/
| |