unsigned long end_pfn = zone_end_pfn(zone);
unsigned long pfn;
- zone->compact_cached_migrate_pfn = start_pfn;
+ zone->compact_cached_migrate_pfn[0] = start_pfn;
+ zone->compact_cached_migrate_pfn[1] = start_pfn;
zone->compact_cached_free_pfn = end_pfn;
zone->compact_blockskip_flush = false;
*/
static void update_pageblock_skip(struct compact_control *cc,
struct page *page, unsigned long nr_isolated,
- bool migrate_scanner)
+ bool set_unsuitable, bool migrate_scanner)
{
struct zone *zone = cc->zone;
+ unsigned long pfn;
if (cc->ignore_skip_hint)
return;
if (!page)
return;
- if (!nr_isolated) {
- unsigned long pfn = page_to_pfn(page);
+ if (nr_isolated)
+ return;
+
+ /*
+ * Only skip pageblocks when all forms of compaction will be known to
+ * fail in the near future.
+ */
+ if (set_unsuitable)
set_pageblock_skip(page);
- /* Update where compaction should restart */
- if (migrate_scanner) {
- if (!cc->finished_update_migrate &&
- pfn > zone->compact_cached_migrate_pfn)
- zone->compact_cached_migrate_pfn = pfn;
- } else {
- if (!cc->finished_update_free &&
- pfn < zone->compact_cached_free_pfn)
- zone->compact_cached_free_pfn = pfn;
- }
+ pfn = page_to_pfn(page);
+
+ /* 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->sync && 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;
}
}
#else
static void update_pageblock_skip(struct compact_control *cc,
struct page *page, unsigned long nr_isolated,
- bool migrate_scanner)
+ bool set_unsuitable, bool migrate_scanner)
{
}
#endif /* CONFIG_COMPACTION */
return true;
}
-static inline bool compact_trylock_irqsave(spinlock_t *lock,
- unsigned long *flags, struct compact_control *cc)
-{
- return compact_checklock_irqsave(lock, flags, false, cc);
-}
-
/* Returns true if the page is within a block suitable for migration to */
static bool suitable_migration_target(struct page *page)
{
/* Update the pageblock-skip if the whole pageblock was scanned */
if (blockpfn == end_pfn)
- update_pageblock_skip(cc, valid_page, total_isolated, false);
+ update_pageblock_skip(cc, valid_page, total_isolated, true,
+ false);
count_compact_events(COMPACTFREE_SCANNED, nr_scanned);
if (total_isolated)
unsigned long flags;
bool locked = false;
struct page *page = NULL, *valid_page = NULL;
- bool skipped_async_unsuitable = false;
+ bool set_unsuitable = true;
const isolate_mode_t mode = (!cc->sync ? ISOLATE_ASYNC_MIGRATE : 0) |
(unevictable ? ISOLATE_UNEVICTABLE : 0);
*/
mt = get_pageblock_migratetype(page);
if (!cc->sync && !migrate_async_suitable(mt)) {
- cc->finished_update_migrate = true;
- skipped_async_unsuitable = true;
+ set_unsuitable = false;
goto next_pageblock;
}
}
/*
* Update the pageblock-skip information and cached scanner pfn,
* if the whole pageblock was scanned without isolating any page.
- * This is not done when pageblock was skipped due to being unsuitable
- * for async compaction, so that eventual sync compaction can try.
*/
- if (low_pfn == end_pfn && !skipped_async_unsuitable)
- update_pageblock_skip(cc, valid_page, nr_isolated, true);
+ if (low_pfn == end_pfn)
+ update_pageblock_skip(cc, valid_page, nr_isolated,
+ set_unsuitable, true);
trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
struct compact_control *cc)
{
struct page *page;
- unsigned long high_pfn, low_pfn, pfn, z_end_pfn;
+ unsigned long block_start_pfn; /* start of current pageblock */
+ unsigned long block_end_pfn; /* end of current pageblock */
+ unsigned long low_pfn; /* lowest pfn scanner is able to scan */
+ unsigned long next_free_pfn; /* start pfn for scaning at next round */
int nr_freepages = cc->nr_freepages;
struct list_head *freelist = &cc->freepages;
* Initialise the free scanner. The starting point is where we last
* successfully isolated from, zone-cached value, or the end of the
* zone when isolating for the first time. We need this aligned to
- * the pageblock boundary, because we do pfn -= pageblock_nr_pages
- * in the for loop.
+ * the pageblock boundary, because we do
+ * block_start_pfn -= pageblock_nr_pages in the for loop.
+ * For ending point, take care when isolating in last pageblock of a
+ * a zone which ends in the middle of a pageblock.
* The low boundary is the end of the pageblock the migration scanner
* is using.
*/
- pfn = cc->free_pfn & ~(pageblock_nr_pages-1);
+ block_start_pfn = cc->free_pfn & ~(pageblock_nr_pages-1);
+ block_end_pfn = min(block_start_pfn + pageblock_nr_pages,
+ zone_end_pfn(zone));
low_pfn = ALIGN(cc->migrate_pfn + 1, pageblock_nr_pages);
/*
- * Take care that if the migration scanner is at the end of the zone
- * that the free scanner does not accidentally move to the next zone
- * in the next isolation cycle.
+ * If no pages are isolated, the block_start_pfn < low_pfn check
+ * will kick in.
*/
- high_pfn = min(low_pfn, pfn);
-
- z_end_pfn = zone_end_pfn(zone);
+ next_free_pfn = 0;
/*
* Isolate free pages until enough are available to migrate the
* pages on cc->migratepages. We stop searching if the migrate
* and free page scanners meet or enough free pages are isolated.
*/
- for (; pfn >= low_pfn && cc->nr_migratepages > nr_freepages;
- pfn -= pageblock_nr_pages) {
+ for (; block_start_pfn >= low_pfn && cc->nr_migratepages > nr_freepages;
+ block_end_pfn = block_start_pfn,
+ block_start_pfn -= pageblock_nr_pages) {
unsigned long isolated;
- unsigned long end_pfn;
/*
* This can iterate a massively long zone without finding any
*/
cond_resched();
- if (!pfn_valid(pfn))
+ if (!pfn_valid(block_start_pfn))
continue;
/*
* i.e. it's possible that all pages within a zones range of
* pages do not belong to a single zone.
*/
- page = pfn_to_page(pfn);
+ page = pfn_to_page(block_start_pfn);
if (page_zone(page) != zone)
continue;
continue;
/* Found a block suitable for isolating free pages from */
- isolated = 0;
-
- /*
- * Take care when isolating in last pageblock of a zone which
- * ends in the middle of a pageblock.
- */
- end_pfn = min(pfn + pageblock_nr_pages, z_end_pfn);
- isolated = isolate_freepages_block(cc, pfn, end_pfn,
- freelist, false);
+ isolated = isolate_freepages_block(cc, block_start_pfn,
+ block_end_pfn, freelist, false);
nr_freepages += isolated;
/*
* looking for free pages, the search will restart here as
* page migration may have returned some pages to the allocator
*/
- if (isolated) {
+ if (isolated && next_free_pfn == 0) {
cc->finished_update_free = true;
- high_pfn = max(high_pfn, pfn);
+ next_free_pfn = block_start_pfn;
}
}
* If we crossed the migrate scanner, we want to keep it that way
* so that compact_finished() may detect this
*/
- if (pfn < low_pfn)
- cc->free_pfn = max(pfn, zone->zone_start_pfn);
- else
- cc->free_pfn = high_pfn;
+ if (block_start_pfn < low_pfn)
+ next_free_pfn = cc->migrate_pfn;
+
+ cc->free_pfn = next_free_pfn;
cc->nr_freepages = nr_freepages;
}
}
/*
- * We cannot control nr_migratepages and nr_freepages fully when migration is
- * running as migrate_pages() has no knowledge of compact_control. When
- * migration is complete, we count the number of pages on the lists by hand.
+ * This is a migrate-callback that "frees" freepages back to the isolated
+ * freelist. All pages on the freelist are from the same zone, so there is no
+ * special handling needed for NUMA.
+ */
+static void compaction_free(struct page *page, unsigned long data)
+{
+ struct compact_control *cc = (struct compact_control *)data;
+
+ list_add(&page->lru, &cc->freepages);
+ cc->nr_freepages++;
+}
+
+/*
+ * We cannot control nr_migratepages fully when migration is running as
+ * migrate_pages() has no knowledge of of compact_control. When migration is
+ * complete, we count the number of pages on the list by hand.
*/
static void update_nr_listpages(struct compact_control *cc)
{
int nr_migratepages = 0;
- int nr_freepages = 0;
struct page *page;
list_for_each_entry(page, &cc->migratepages, lru)
nr_migratepages++;
- list_for_each_entry(page, &cc->freepages, lru)
- nr_freepages++;
cc->nr_migratepages = nr_migratepages;
- cc->nr_freepages = nr_freepages;
}
/* possible outcome of isolate_migratepages */
/* Compaction run completes if the migrate and free scanner meet */
if (cc->free_pfn <= cc->migrate_pfn) {
/* Let the next compaction start anew. */
- zone->compact_cached_migrate_pfn = zone->zone_start_pfn;
+ zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
+ zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
zone->compact_cached_free_pfn = zone_end_pfn(zone);
/*
* information on where the scanners should start but check that it
* is initialised by ensuring the values are within zone boundaries.
*/
- cc->migrate_pfn = zone->compact_cached_migrate_pfn;
+ cc->migrate_pfn = zone->compact_cached_migrate_pfn[cc->sync];
cc->free_pfn = zone->compact_cached_free_pfn;
if (cc->free_pfn < start_pfn || cc->free_pfn > end_pfn) {
cc->free_pfn = end_pfn & ~(pageblock_nr_pages-1);
}
if (cc->migrate_pfn < start_pfn || cc->migrate_pfn > end_pfn) {
cc->migrate_pfn = start_pfn;
- zone->compact_cached_migrate_pfn = cc->migrate_pfn;
+ zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
+ zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
}
trace_mm_compaction_begin(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn);
nr_migrate = cc->nr_migratepages;
err = migrate_pages(&cc->migratepages, compaction_alloc,
- (unsigned long)cc,
+ compaction_free, (unsigned long)cc,
cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC,
MR_COMPACTION);
update_nr_listpages(cc);
if (zone_watermark_ok(zone, cc->order,
low_wmark_pages(zone), 0, 0))
compaction_defer_reset(zone, cc->order, false);
- /* Currently async compaction is never deferred. */
- else if (cc->sync)
- defer_compaction(zone, cc->order);
}
VM_BUG_ON(!list_empty(&cc->freepages));
projects / mirror_ubuntu-bionic-kernel.git / blobdiff