static unsigned long release_freepages(struct list_head *freelist)
{
struct page *page, *next;
- unsigned long count = 0;
+ unsigned long high_pfn = 0;
list_for_each_entry_safe(page, next, freelist, lru) {
+ unsigned long pfn = page_to_pfn(page);
list_del(&page->lru);
__free_page(page);
- count++;
+ if (pfn > high_pfn)
+ high_pfn = pfn;
}
- return count;
+ return high_pfn;
}
static void map_pages(struct list_head *list)
/* Update where async and sync compaction should restart */
if (migrate_scanner) {
- if (cc->finished_update_migrate)
- return;
if (pfn > zone->compact_cached_migrate_pfn[0])
zone->compact_cached_migrate_pfn[0] = pfn;
if (cc->mode != MIGRATE_ASYNC &&
pfn > zone->compact_cached_migrate_pfn[1])
zone->compact_cached_migrate_pfn[1] = pfn;
} else {
- if (cc->finished_update_free)
- return;
if (pfn < zone->compact_cached_free_pfn)
zone->compact_cached_free_pfn = pfn;
}
del_page_from_lru_list(page, lruvec, page_lru(page));
isolate_success:
- cc->finished_update_migrate = true;
list_add(&page->lru, migratelist);
cc->nr_migratepages++;
nr_isolated++;
isolate_start_pfn :
block_start_pfn - pageblock_nr_pages;
- /*
- * Set a flag that we successfully isolated in this pageblock.
- * In the next loop iteration, zone->compact_cached_free_pfn
- * will not be updated and thus it will effectively contain the
- * highest pageblock we isolated pages from.
- */
- if (isolated)
- cc->finished_update_free = true;
-
/*
* isolate_freepages_block() might have aborted due to async
* compaction being contended
unsigned long end_pfn = zone_end_pfn(zone);
const int migratetype = gfpflags_to_migratetype(cc->gfp_mask);
const bool sync = cc->mode != MIGRATE_ASYNC;
+ unsigned long last_migrated_pfn = 0;
ret = compaction_suitable(zone, cc->order, cc->alloc_flags,
cc->classzone_idx);
while ((ret = compact_finished(zone, cc, migratetype)) ==
COMPACT_CONTINUE) {
int err;
+ unsigned long isolate_start_pfn = cc->migrate_pfn;
switch (isolate_migratepages(zone, cc)) {
case ISOLATE_ABORT:
cc->nr_migratepages = 0;
goto out;
case ISOLATE_NONE:
- continue;
+ /*
+ * We haven't isolated and migrated anything, but
+ * there might still be unflushed migrations from
+ * previous cc->order aligned block.
+ */
+ goto check_drain;
case ISOLATE_SUCCESS:
;
}
goto out;
}
}
+
+ /*
+ * Record where we could have freed pages by migration and not
+ * yet flushed them to buddy allocator. We use the pfn that
+ * isolate_migratepages() started from in this loop iteration
+ * - this is the lowest page that could have been isolated and
+ * then freed by migration.
+ */
+ if (!last_migrated_pfn)
+ last_migrated_pfn = isolate_start_pfn;
+
+check_drain:
+ /*
+ * Has the migration scanner moved away from the previous
+ * cc->order aligned block where we migrated from? If yes,
+ * flush the pages that were freed, so that they can merge and
+ * compact_finished() can detect immediately if allocation
+ * would succeed.
+ */
+ if (cc->order > 0 && last_migrated_pfn) {
+ int cpu;
+ unsigned long current_block_start =
+ cc->migrate_pfn & ~((1UL << cc->order) - 1);
+
+ if (last_migrated_pfn < current_block_start) {
+ cpu = get_cpu();
+ lru_add_drain_cpu(cpu);
+ drain_local_pages(zone);
+ put_cpu();
+ /* No more flushing until we migrate again */
+ last_migrated_pfn = 0;
+ }
+ }
+
}
out:
- /* Release free pages and check accounting */
- cc->nr_freepages -= release_freepages(&cc->freepages);
- VM_BUG_ON(cc->nr_freepages != 0);
+ /*
+ * Release free pages and update where the free scanner should restart,
+ * so we don't leave any returned pages behind in the next attempt.
+ */
+ if (cc->nr_freepages > 0) {
+ unsigned long free_pfn = release_freepages(&cc->freepages);
+
+ cc->nr_freepages = 0;
+ VM_BUG_ON(free_pfn == 0);
+ /* The cached pfn is always the first in a pageblock */
+ free_pfn &= ~(pageblock_nr_pages-1);
+ /*
+ * Only go back, not forward. The cached pfn might have been
+ * already reset to zone end in compact_finished()
+ */
+ if (free_pfn > zone->compact_cached_free_pfn)
+ zone->compact_cached_free_pfn = free_pfn;
+ }
trace_mm_compaction_end(ret);
* @mode: The migration mode for async, sync light, or sync migration
* @contended: Return value that determines if compaction was aborted due to
* need_resched() or lock contention
- * @candidate_zone: Return the zone where we think allocation should succeed
*
* This is the main entry point for direct page compaction.
*/
unsigned long try_to_compact_pages(struct zonelist *zonelist,
int order, gfp_t gfp_mask, nodemask_t *nodemask,
enum migrate_mode mode, int *contended,
- int alloc_flags, int classzone_idx,
- struct zone **candidate_zone)
+ int alloc_flags, int classzone_idx)
{
enum zone_type high_zoneidx = gfp_zone(gfp_mask);
int may_enter_fs = gfp_mask & __GFP_FS;
/* If a normal allocation would succeed, stop compacting */
if (zone_watermark_ok(zone, order, low_wmark_pages(zone),
classzone_idx, alloc_flags)) {
- *candidate_zone = zone;
/*
* We think the allocation will succeed in this zone,
* but it is not certain, hence the false. The caller
goto break_loop;
}
- if (mode != MIGRATE_ASYNC) {
+ if (mode != MIGRATE_ASYNC && status == COMPACT_COMPLETE) {
/*
* We think that allocation won't succeed in this zone
* so we defer compaction there. If it ends up
projects / deliverable / linux.git / blobdiff