From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 11 Feb 2006 13:39:14 -0800 (PST) From: Christoph Lameter Subject: Skip reclaim_mapped determination if we do not swap Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org, nickpiggin@yahoo.com.au, marcelo.tosatti@cyclades.com List-ID: This puts the variables and the way to get to reclaim_mapped in one block. And allows zone_reclaim or other things to skip the determination (maybe this whole block of code does not belong into refill_inactive_zone()?) Signed-off-by: Christoph Lameter Index: linux-2.6.16-rc2/mm/vmscan.c =================================================================== --- linux-2.6.16-rc2.orig/mm/vmscan.c 2006-02-11 13:29:51.000000000 -0800 +++ linux-2.6.16-rc2/mm/vmscan.c 2006-02-11 13:31:15.000000000 -0800 @@ -1180,9 +1180,43 @@ refill_inactive_zone(struct zone *zone, struct page *page; struct pagevec pvec; int reclaim_mapped = 0; - long mapped_ratio; - long distress; - long swap_tendency; + + if (sc->may_swap) { + long mapped_ratio; + long distress; + long swap_tendency; + + /* + * `distress' is a measure of how much trouble we're having reclaiming + * pages. 0 -> no problems. 100 -> great trouble. + */ + distress = 100 >> zone->prev_priority; + + /* + * The point of this algorithm is to decide when to start reclaiming + * mapped memory instead of just pagecache. Work out how much memory + * is mapped. + */ + mapped_ratio = (sc->nr_mapped * 100) / total_memory; + + /* + * Now decide how much we really want to unmap some pages. The mapped + * ratio is downgraded - just because there's a lot of mapped memory + * doesn't necessarily mean that page reclaim isn't succeeding. + * + * The distress ratio is important - we don't want to start going oom. + * + * A 100% value of vm_swappiness overrides this algorithm altogether. + */ + swap_tendency = mapped_ratio / 2 + distress + vm_swappiness; + + /* + * Now use this metric to decide whether to start moving mapped memory + * onto the inactive list. + */ + if (swap_tendency >= 100) + reclaim_mapped = 1; + } lru_add_drain(); spin_lock_irq(&zone->lru_lock); @@ -1192,37 +1226,6 @@ refill_inactive_zone(struct zone *zone, zone->nr_active -= pgmoved; spin_unlock_irq(&zone->lru_lock); - /* - * `distress' is a measure of how much trouble we're having reclaiming - * pages. 0 -> no problems. 100 -> great trouble. - */ - distress = 100 >> zone->prev_priority; - - /* - * The point of this algorithm is to decide when to start reclaiming - * mapped memory instead of just pagecache. Work out how much memory - * is mapped. - */ - mapped_ratio = (sc->nr_mapped * 100) / total_memory; - - /* - * Now decide how much we really want to unmap some pages. The mapped - * ratio is downgraded - just because there's a lot of mapped memory - * doesn't necessarily mean that page reclaim isn't succeeding. - * - * The distress ratio is important - we don't want to start going oom. - * - * A 100% value of vm_swappiness overrides this algorithm altogether. - */ - swap_tendency = mapped_ratio / 2 + distress + vm_swappiness; - - /* - * Now use this metric to decide whether to start moving mapped memory - * onto the inactive list. - */ - if (swap_tendency >= 100 && sc->may_swap) - reclaim_mapped = 1; - while (!list_empty(&l_hold)) { cond_resched(); page = lru_to_page(&l_hold); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org