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Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c123
1 files changed, 81 insertions, 42 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 13cb7a961b31..e5acb9714436 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -157,7 +157,7 @@ EXPORT_SYMBOL(__ClearPageMovable);
* allocation success. 1 << compact_defer_shift, compactions are skipped up
* to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
*/
-void defer_compaction(struct zone *zone, int order)
+static void defer_compaction(struct zone *zone, int order)
{
zone->compact_considered = 0;
zone->compact_defer_shift++;
@@ -172,7 +172,7 @@ void defer_compaction(struct zone *zone, int order)
}
/* Returns true if compaction should be skipped this time */
-bool compaction_deferred(struct zone *zone, int order)
+static bool compaction_deferred(struct zone *zone, int order)
{
unsigned long defer_limit = 1UL << zone->compact_defer_shift;
@@ -209,7 +209,7 @@ void compaction_defer_reset(struct zone *zone, int order,
}
/* Returns true if restarting compaction after many failures */
-bool compaction_restarting(struct zone *zone, int order)
+static bool compaction_restarting(struct zone *zone, int order)
{
if (order < zone->compact_order_failed)
return false;
@@ -237,7 +237,7 @@ static void reset_cached_positions(struct zone *zone)
}
/*
- * Compound pages of >= pageblock_order should consistenly be skipped until
+ * Compound pages of >= pageblock_order should consistently be skipped until
* released. It is always pointless to compact pages of such order (if they are
* migratable), and the pageblocks they occupy cannot contain any free pages.
*/
@@ -804,7 +804,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
unsigned long nr_scanned = 0, nr_isolated = 0;
struct lruvec *lruvec;
unsigned long flags = 0;
- bool locked = false;
+ struct lruvec *locked = NULL;
struct page *page = NULL, *valid_page = NULL;
unsigned long start_pfn = low_pfn;
bool skip_on_failure = false;
@@ -868,11 +868,20 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* contention, to give chance to IRQs. Abort completely if
* a fatal signal is pending.
*/
- if (!(low_pfn % SWAP_CLUSTER_MAX)
- && compact_unlock_should_abort(&pgdat->lru_lock,
- flags, &locked, cc)) {
- low_pfn = 0;
- goto fatal_pending;
+ if (!(low_pfn % SWAP_CLUSTER_MAX)) {
+ if (locked) {
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
+ }
+
+ if (fatal_signal_pending(current)) {
+ cc->contended = true;
+
+ low_pfn = 0;
+ goto fatal_pending;
+ }
+
+ cond_resched();
}
if (!pfn_valid_within(low_pfn))
@@ -890,6 +899,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
if (!cc->ignore_skip_hint && get_pageblock_skip(page)) {
low_pfn = end_pfn;
+ page = NULL;
goto isolate_abort;
}
valid_page = page;
@@ -943,9 +953,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
if (unlikely(__PageMovable(page)) &&
!PageIsolated(page)) {
if (locked) {
- spin_unlock_irqrestore(&pgdat->lru_lock,
- flags);
- locked = false;
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
}
if (!isolate_movable_page(page, isolate_mode))
@@ -971,10 +980,34 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page))
goto isolate_fail;
+ /*
+ * Be careful not to clear PageLRU until after we're
+ * sure the page is not being freed elsewhere -- the
+ * page release code relies on it.
+ */
+ if (unlikely(!get_page_unless_zero(page)))
+ goto isolate_fail;
+
+ if (__isolate_lru_page_prepare(page, isolate_mode) != 0)
+ goto isolate_fail_put;
+
+ /* Try isolate the page */
+ if (!TestClearPageLRU(page))
+ goto isolate_fail_put;
+
+ rcu_read_lock();
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+
/* If we already hold the lock, we can skip some rechecking */
- if (!locked) {
- locked = compact_lock_irqsave(&pgdat->lru_lock,
- &flags, cc);
+ if (lruvec != locked) {
+ if (locked)
+ unlock_page_lruvec_irqrestore(locked, flags);
+
+ compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
+ locked = lruvec;
+ rcu_read_unlock();
+
+ lruvec_memcg_debug(lruvec, page);
/* Try get exclusive access under lock */
if (!skip_updated) {
@@ -983,10 +1016,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
goto isolate_abort;
}
- /* Recheck PageLRU and PageCompound under lock */
- if (!PageLRU(page))
- goto isolate_fail;
-
/*
* Page become compound since the non-locked check,
* and it's on LRU. It can only be a THP so the order
@@ -994,15 +1023,11 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
*/
if (unlikely(PageCompound(page) && !cc->alloc_contig)) {
low_pfn += compound_nr(page) - 1;
- goto isolate_fail;
+ SetPageLRU(page);
+ goto isolate_fail_put;
}
- }
-
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
-
- /* Try isolate the page */
- if (__isolate_lru_page(page, isolate_mode) != 0)
- goto isolate_fail;
+ } else
+ rcu_read_unlock();
/* The whole page is taken off the LRU; skip the tail pages. */
if (PageCompound(page))
@@ -1032,6 +1057,15 @@ isolate_success:
}
continue;
+
+isolate_fail_put:
+ /* Avoid potential deadlock in freeing page under lru_lock */
+ if (locked) {
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
+ }
+ put_page(page);
+
isolate_fail:
if (!skip_on_failure)
continue;
@@ -1043,8 +1077,8 @@ isolate_fail:
*/
if (nr_isolated) {
if (locked) {
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- locked = false;
+ unlock_page_lruvec_irqrestore(locked, flags);
+ locked = NULL;
}
putback_movable_pages(&cc->migratepages);
cc->nr_migratepages = 0;
@@ -1068,9 +1102,15 @@ isolate_fail:
if (unlikely(low_pfn > end_pfn))
low_pfn = end_pfn;
+ page = NULL;
+
isolate_abort:
if (locked)
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ unlock_page_lruvec_irqrestore(locked, flags);
+ if (page) {
+ SetPageLRU(page);
+ put_page(page);
+ }
/*
* Updated the cached scanner pfn once the pageblock has been scanned
@@ -2070,13 +2110,6 @@ static enum compact_result compact_finished(struct compact_control *cc)
return ret;
}
-/*
- * compaction_suitable: Is this suitable to run compaction on this zone now?
- * Returns
- * COMPACT_SKIPPED - If there are too few free pages for compaction
- * COMPACT_SUCCESS - If the allocation would succeed without compaction
- * COMPACT_CONTINUE - If compaction should run now
- */
static enum compact_result __compaction_suitable(struct zone *zone, int order,
unsigned int alloc_flags,
int highest_zoneidx,
@@ -2120,6 +2153,13 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,
return COMPACT_CONTINUE;
}
+/*
+ * compaction_suitable: Is this suitable to run compaction on this zone now?
+ * Returns
+ * COMPACT_SKIPPED - If there are too few free pages for compaction
+ * COMPACT_SUCCESS - If the allocation would succeed without compaction
+ * COMPACT_CONTINUE - If compaction should run now
+ */
enum compact_result compaction_suitable(struct zone *zone, int order,
unsigned int alloc_flags,
int highest_zoneidx)
@@ -2275,7 +2315,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) {
int err;
- unsigned long start_pfn = cc->migrate_pfn;
+ unsigned long iteration_start_pfn = cc->migrate_pfn;
/*
* Avoid multiple rescans which can happen if a page cannot be
@@ -2287,7 +2327,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
*/
cc->rescan = false;
if (pageblock_start_pfn(last_migrated_pfn) ==
- pageblock_start_pfn(start_pfn)) {
+ pageblock_start_pfn(iteration_start_pfn)) {
cc->rescan = true;
}
@@ -2311,8 +2351,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
goto check_drain;
case ISOLATE_SUCCESS:
update_cached = false;
- last_migrated_pfn = start_pfn;
- ;
+ last_migrated_pfn = iteration_start_pfn;
}
err = migrate_pages(&cc->migratepages, compaction_alloc,
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-18 16:47:18 +0300