thp: use compaction in kswapd for GFP_ATOMIC order > 0

This takes advantage of memory compaction to properly generate pages of
order > 0 if regular page reclaim fails and priority level becomes more
severe and we don't reach the proper watermarks.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli
2011-01-13 15:47:11 -08:00
committed by Linus Torvalds
parent 878aee7d6b
commit 5a03b051ed
3 changed files with 54 additions and 18 deletions

View File

@ -42,6 +42,8 @@ struct compact_control {
unsigned int order; /* order a direct compactor needs */
int migratetype; /* MOVABLE, RECLAIMABLE etc */
struct zone *zone;
int compact_mode;
};
static unsigned long release_freepages(struct list_head *freelist)
@ -382,10 +384,10 @@ static void update_nr_listpages(struct compact_control *cc)
}
static int compact_finished(struct zone *zone,
struct compact_control *cc)
struct compact_control *cc)
{
unsigned int order;
unsigned long watermark = low_wmark_pages(zone) + (1 << cc->order);
unsigned long watermark;
if (fatal_signal_pending(current))
return COMPACT_PARTIAL;
@ -395,12 +397,27 @@ static int compact_finished(struct zone *zone,
return COMPACT_COMPLETE;
/* Compaction run is not finished if the watermark is not met */
if (cc->compact_mode != COMPACT_MODE_KSWAPD)
watermark = low_wmark_pages(zone);
else
watermark = high_wmark_pages(zone);
watermark += (1 << cc->order);
if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0))
return COMPACT_CONTINUE;
if (cc->order == -1)
return COMPACT_CONTINUE;
/*
* Generating only one page of the right order is not enough
* for kswapd, we must continue until we're above the high
* watermark as a pool for high order GFP_ATOMIC allocations
* too.
*/
if (cc->compact_mode == COMPACT_MODE_KSWAPD)
return COMPACT_CONTINUE;
/* Direct compactor: Is a suitable page free? */
for (order = cc->order; order < MAX_ORDER; order++) {
/* Job done if page is free of the right migratetype */
@ -514,8 +531,9 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
}
unsigned long compact_zone_order(struct zone *zone,
int order, gfp_t gfp_mask,
bool sync)
int order, gfp_t gfp_mask,
bool sync,
int compact_mode)
{
struct compact_control cc = {
.nr_freepages = 0,
@ -524,6 +542,7 @@ unsigned long compact_zone_order(struct zone *zone,
.migratetype = allocflags_to_migratetype(gfp_mask),
.zone = zone,
.sync = sync,
.compact_mode = compact_mode,
};
INIT_LIST_HEAD(&cc.freepages);
INIT_LIST_HEAD(&cc.migratepages);
@ -569,7 +588,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
nodemask) {
int status;
status = compact_zone_order(zone, order, gfp_mask, sync);
status = compact_zone_order(zone, order, gfp_mask, sync,
COMPACT_MODE_DIRECT_RECLAIM);
rc = max(status, rc);
/* If a normal allocation would succeed, stop compacting */
@ -600,6 +620,7 @@ static int compact_node(int nid)
.nr_freepages = 0,
.nr_migratepages = 0,
.order = -1,
.compact_mode = COMPACT_MODE_DIRECT_RECLAIM,
};
zone = &pgdat->node_zones[zoneid];