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->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;
}
}
#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 */
}
/* async aborts if taking too long or contended */
- if (!cc->sync) {
+ if (cc->mode == MIGRATE_ASYNC) {
cc->contended = true;
return false;
}
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 last_pageblock_nr = 0, pageblock_nr;
unsigned long nr_scanned = 0, nr_isolated = 0;
struct list_head *migratelist = &cc->migratepages;
- isolate_mode_t mode = 0;
struct lruvec *lruvec;
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->mode == MIGRATE_ASYNC ?
+ ISOLATE_ASYNC_MIGRATE : 0) |
+ (unevictable ? ISOLATE_UNEVICTABLE : 0);
/*
* Ensure that there are not too many pages isolated from the LRU
*/
while (unlikely(too_many_isolated(zone))) {
/* async migration should just abort */
- if (!cc->sync)
+ if (cc->mode == MIGRATE_ASYNC)
return 0;
congestion_wait(BLK_RW_ASYNC, HZ/10);
return 0;
}
+ if (cond_resched()) {
+ /* Async terminates prematurely on need_resched() */
+ if (cc->mode == MIGRATE_ASYNC)
+ return 0;
+ }
+
/* Time to isolate some pages for migration */
- cond_resched();
for (; low_pfn < end_pfn; low_pfn++) {
/* give a chance to irqs before checking need_resched() */
if (locked && !(low_pfn % SWAP_CLUSTER_MAX)) {
* the minimum amount of work satisfies the allocation
*/
mt = get_pageblock_migratetype(page);
- if (!cc->sync && !migrate_async_suitable(mt)) {
- cc->finished_update_migrate = true;
- skipped_async_unsuitable = true;
+ if (cc->mode == MIGRATE_ASYNC &&
+ !migrate_async_suitable(mt)) {
+ set_unsuitable = false;
goto next_pageblock;
}
}
continue;
}
- if (!cc->sync)
- mode |= ISOLATE_ASYNC_MIGRATE;
-
- if (unevictable)
- mode |= ISOLATE_UNEVICTABLE;
-
lruvec = mem_cgroup_page_lruvec(page, zone);
/* Try isolate the page */
/*
* 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);
/*
int ret;
unsigned long start_pfn = zone->zone_start_pfn;
unsigned long end_pfn = zone_end_pfn(zone);
+ const bool sync = cc->mode != MIGRATE_ASYNC;
ret = compaction_suitable(zone, cc->order);
switch (ret) {
* 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[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,
- cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC,
+ compaction_free, (unsigned long)cc, cc->mode,
MR_COMPACTION);
update_nr_listpages(cc);
nr_remaining = cc->nr_migratepages;
return ret;
}
-static unsigned long compact_zone_order(struct zone *zone,
- int order, gfp_t gfp_mask,
- bool sync, bool *contended)
+static unsigned long compact_zone_order(struct zone *zone, int order,
+ gfp_t gfp_mask, enum migrate_mode mode, bool *contended)
{
unsigned long ret;
struct compact_control cc = {
.order = order,
.migratetype = allocflags_to_migratetype(gfp_mask),
.zone = zone,
- .sync = sync,
+ .mode = mode,
};
INIT_LIST_HEAD(&cc.freepages);
INIT_LIST_HEAD(&cc.migratepages);
* @order: The order of the current allocation
* @gfp_mask: The GFP mask of the current allocation
* @nodemask: The allowed nodes to allocate from
- * @sync: Whether migration is synchronous or not
+ * @mode: The migration mode for async, sync light, or sync migration
* @contended: Return value that is true if compaction was aborted due to lock contention
* @page: Optionally capture a free page of the requested order during compaction
*
*/
unsigned long try_to_compact_pages(struct zonelist *zonelist,
int order, gfp_t gfp_mask, nodemask_t *nodemask,
- bool sync, bool *contended)
+ enum migrate_mode mode, bool *contended)
{
enum zone_type high_zoneidx = gfp_zone(gfp_mask);
int may_enter_fs = gfp_mask & __GFP_FS;
nodemask) {
int status;
- status = compact_zone_order(zone, order, gfp_mask, sync,
+ status = compact_zone_order(zone, order, gfp_mask, mode,
contended);
rc = max(status, rc);
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));
{
struct compact_control cc = {
.order = order,
- .sync = false,
+ .mode = MIGRATE_ASYNC,
};
if (!order)
{
struct compact_control cc = {
.order = -1,
- .sync = true,
+ .mode = MIGRATE_SYNC,
+ .ignore_skip_hint = true,
};
__compact_pgdat(NODE_DATA(nid), &cc);