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| author | Christoph Lameter <clameter@engr.sgi.com> | 2006-02-01 03:05:25 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-01 08:53:14 -0800 |
| commit | 8928862398fef04a137e5673ac5fa9e797960c87 (patch) | |
| tree | 141f91c4dd56d323e6f5ce2d47cd1f1d22177aa7 /mm/vmscan.c | |
| parent | 537421be79b94bcf620467f50dd9e38b739c2a00 (diff) | |
| download | lwn-8928862398fef04a137e5673ac5fa9e797960c87.tar.gz lwn-8928862398fef04a137e5673ac5fa9e797960c87.zip | |
[PATCH] Optimize off-node performance of zone reclaim
Ensure that the performance of off node pages stays the same as before.
Off node pagefault tests showed an 18% drop in performance without this
patch.
- Increase the timeout to 30 seconds to reduce the overhead.
- Move all code possible out of the off node hot path for zone reclaim
(Sorry Andrew, the struct initialization had to be sacrificed).
The read_page_state() bit us there.
- Check first for the timeout before any other checks.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 2e34b61a70c7..465bfa54dfd6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1589,24 +1589,20 @@ int zone_reclaim_mode __read_mostly; /* * Mininum time between zone reclaim scans */ -#define ZONE_RECLAIM_INTERVAL HZ/2 +#define ZONE_RECLAIM_INTERVAL 30*HZ /* * Try to free up some pages from this zone through reclaim. */ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) { - int nr_pages = 1 << order; + int nr_pages; struct task_struct *p = current; struct reclaim_state reclaim_state; - struct scan_control sc = { - .gfp_mask = gfp_mask, - .may_writepage = 0, - .may_swap = 0, - .nr_mapped = read_page_state(nr_mapped), - .nr_scanned = 0, - .nr_reclaimed = 0, - .priority = 0 - }; + struct scan_control sc; + + if (time_before(jiffies, + zone->last_unsuccessful_zone_reclaim + ZONE_RECLAIM_INTERVAL)) + return 0; if (!(gfp_mask & __GFP_WAIT) || zone->zone_pgdat->node_id != numa_node_id() || @@ -1614,12 +1610,17 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) atomic_read(&zone->reclaim_in_progress) > 0) return 0; - if (time_before(jiffies, - zone->last_unsuccessful_zone_reclaim + ZONE_RECLAIM_INTERVAL)) - return 0; + sc.may_writepage = 0; + sc.may_swap = 0; + sc.nr_scanned = 0; + sc.nr_reclaimed = 0; + sc.priority = 0; + sc.nr_mapped = read_page_state(nr_mapped); + sc.gfp_mask = gfp_mask; disable_swap_token(); + nr_pages = 1 << order; if (nr_pages > SWAP_CLUSTER_MAX) sc.swap_cluster_max = nr_pages; else |