diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/migrate.c | 174 |
1 files changed, 106 insertions, 68 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 586a32bdaa71..d436f35fa145 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1414,6 +1414,11 @@ static inline int try_split_folio(struct folio *folio, struct list_head *split_f return rc; } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#define NR_MAX_BATCHED_MIGRATION HPAGE_PMD_NR +#else +#define NR_MAX_BATCHED_MIGRATION 512 +#endif #define NR_MAX_MIGRATE_PAGES_RETRY 10 struct migrate_pages_stats { @@ -1515,40 +1520,15 @@ static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page, return nr_failed; } -/* - * migrate_pages - migrate the folios specified in a list, to the free folios - * supplied as the target for the page migration - * - * @from: The list of folios to be migrated. - * @get_new_page: The function used to allocate free folios to be used - * as the target of the folio migration. - * @put_new_page: The function used to free target folios if migration - * fails, or NULL if no special handling is necessary. - * @private: Private data to be passed on to get_new_page() - * @mode: The migration mode that specifies the constraints for - * folio migration, if any. - * @reason: The reason for folio migration. - * @ret_succeeded: Set to the number of folios migrated successfully if - * the caller passes a non-NULL pointer. - * - * The function returns after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no folios - * are movable any more because the list has become empty or no retryable folios - * exist any more. It is caller's responsibility to call putback_movable_pages() - * only if ret != 0. - * - * Returns the number of {normal folio, large folio, hugetlb} that were not - * migrated, or an error code. The number of large folio splits will be - * considered as the number of non-migrated large folio, no matter how many - * split folios of the large folio are migrated successfully. - */ -int migrate_pages(struct list_head *from, new_page_t get_new_page, +static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, free_page_t put_new_page, unsigned long private, - enum migrate_mode mode, int reason, unsigned int *ret_succeeded) + enum migrate_mode mode, int reason, struct list_head *ret_folios, + struct migrate_pages_stats *stats) { int retry = 1; int large_retry = 1; int thp_retry = 1; - int nr_failed; + int nr_failed = 0; int nr_retry_pages = 0; int nr_large_failed = 0; int pass = 0; @@ -1556,20 +1536,9 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, bool is_thp = false; struct folio *folio, *folio2; int rc, nr_pages; - LIST_HEAD(ret_folios); LIST_HEAD(split_folios); bool nosplit = (reason == MR_NUMA_MISPLACED); bool no_split_folio_counting = false; - struct migrate_pages_stats stats; - - trace_mm_migrate_pages_start(mode, reason); - - memset(&stats, 0, sizeof(stats)); - rc = migrate_hugetlbs(from, get_new_page, put_new_page, private, mode, reason, - &stats, &ret_folios); - if (rc < 0) - goto out; - nr_failed = rc; split_folio_migration: for (pass = 0; @@ -1581,12 +1550,6 @@ split_folio_migration: nr_retry_pages = 0; list_for_each_entry_safe(folio, folio2, from, lru) { - /* Retried hugetlb folios will be kept in list */ - if (folio_test_hugetlb(folio)) { - list_move_tail(&folio->lru, &ret_folios); - continue; - } - /* * Large folio statistics is based on the source large * folio. Capture required information that might get @@ -1600,15 +1563,14 @@ split_folio_migration: rc = unmap_and_move(get_new_page, put_new_page, private, folio, pass > 2, mode, - reason, &ret_folios); + reason, ret_folios); /* * The rules are: * Success: folio will be freed * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list * -ENOSYS: stay on the from list - * Other errno: put on ret_folios list then splice to - * from list + * Other errno: put on ret_folios list */ switch(rc) { /* @@ -1625,17 +1587,17 @@ split_folio_migration: /* Large folio migration is unsupported */ if (is_large) { nr_large_failed++; - stats.nr_thp_failed += is_thp; + stats->nr_thp_failed += is_thp; if (!try_split_folio(folio, &split_folios)) { - stats.nr_thp_split += is_thp; + stats->nr_thp_split += is_thp; break; } } else if (!no_split_folio_counting) { nr_failed++; } - stats.nr_failed_pages += nr_pages; - list_move_tail(&folio->lru, &ret_folios); + stats->nr_failed_pages += nr_pages; + list_move_tail(&folio->lru, ret_folios); break; case -ENOMEM: /* @@ -1644,13 +1606,13 @@ split_folio_migration: */ if (is_large) { nr_large_failed++; - stats.nr_thp_failed += is_thp; + stats->nr_thp_failed += is_thp; /* Large folio NUMA faulting doesn't split to retry. */ if (!nosplit) { int ret = try_split_folio(folio, &split_folios); if (!ret) { - stats.nr_thp_split += is_thp; + stats->nr_thp_split += is_thp; break; } else if (reason == MR_LONGTERM_PIN && ret == -EAGAIN) { @@ -1668,17 +1630,17 @@ split_folio_migration: nr_failed++; } - stats.nr_failed_pages += nr_pages + nr_retry_pages; + stats->nr_failed_pages += nr_pages + nr_retry_pages; /* * There might be some split folios of fail-to-migrate large - * folios left in split_folios list. Move them back to migration + * folios left in split_folios list. Move them to ret_folios * list so that they could be put back to the right list by * the caller otherwise the folio refcnt will be leaked. */ - list_splice_init(&split_folios, from); + list_splice_init(&split_folios, ret_folios); /* nr_failed isn't updated for not used */ nr_large_failed += large_retry; - stats.nr_thp_failed += thp_retry; + stats->nr_thp_failed += thp_retry; goto out; case -EAGAIN: if (is_large) { @@ -1690,8 +1652,8 @@ split_folio_migration: nr_retry_pages += nr_pages; break; case MIGRATEPAGE_SUCCESS: - stats.nr_succeeded += nr_pages; - stats.nr_thp_succeeded += is_thp; + stats->nr_succeeded += nr_pages; + stats->nr_thp_succeeded += is_thp; break; default: /* @@ -1702,20 +1664,20 @@ split_folio_migration: */ if (is_large) { nr_large_failed++; - stats.nr_thp_failed += is_thp; + stats->nr_thp_failed += is_thp; } else if (!no_split_folio_counting) { nr_failed++; } - stats.nr_failed_pages += nr_pages; + stats->nr_failed_pages += nr_pages; break; } } } nr_failed += retry; nr_large_failed += large_retry; - stats.nr_thp_failed += thp_retry; - stats.nr_failed_pages += nr_retry_pages; + stats->nr_thp_failed += thp_retry; + stats->nr_failed_pages += nr_retry_pages; /* * Try to migrate split folios of fail-to-migrate large folios, no * nr_failed counting in this round, since all split folios of a @@ -1726,7 +1688,7 @@ split_folio_migration: * Move non-migrated folios (after NR_MAX_MIGRATE_PAGES_RETRY * retries) to ret_folios to avoid migrating them again. */ - list_splice_init(from, &ret_folios); + list_splice_init(from, ret_folios); list_splice_init(&split_folios, from); no_split_folio_counting = true; retry = 1; @@ -1735,6 +1697,82 @@ split_folio_migration: rc = nr_failed + nr_large_failed; out: + return rc; +} + +/* + * migrate_pages - migrate the folios specified in a list, to the free folios + * supplied as the target for the page migration + * + * @from: The list of folios to be migrated. + * @get_new_page: The function used to allocate free folios to be used + * as the target of the folio migration. + * @put_new_page: The function used to free target folios if migration + * fails, or NULL if no special handling is necessary. + * @private: Private data to be passed on to get_new_page() + * @mode: The migration mode that specifies the constraints for + * folio migration, if any. + * @reason: The reason for folio migration. + * @ret_succeeded: Set to the number of folios migrated successfully if + * the caller passes a non-NULL pointer. + * + * The function returns after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no folios + * are movable any more because the list has become empty or no retryable folios + * exist any more. It is caller's responsibility to call putback_movable_pages() + * only if ret != 0. + * + * Returns the number of {normal folio, large folio, hugetlb} that were not + * migrated, or an error code. The number of large folio splits will be + * considered as the number of non-migrated large folio, no matter how many + * split folios of the large folio are migrated successfully. + */ +int migrate_pages(struct list_head *from, new_page_t get_new_page, + free_page_t put_new_page, unsigned long private, + enum migrate_mode mode, int reason, unsigned int *ret_succeeded) +{ + int rc, rc_gather; + int nr_pages; + struct folio *folio, *folio2; + LIST_HEAD(folios); + LIST_HEAD(ret_folios); + struct migrate_pages_stats stats; + + trace_mm_migrate_pages_start(mode, reason); + + memset(&stats, 0, sizeof(stats)); + + rc_gather = migrate_hugetlbs(from, get_new_page, put_new_page, private, + mode, reason, &stats, &ret_folios); + if (rc_gather < 0) + goto out; +again: + nr_pages = 0; + list_for_each_entry_safe(folio, folio2, from, lru) { + /* Retried hugetlb folios will be kept in list */ + if (folio_test_hugetlb(folio)) { + list_move_tail(&folio->lru, &ret_folios); + continue; + } + + nr_pages += folio_nr_pages(folio); + if (nr_pages > NR_MAX_BATCHED_MIGRATION) + break; + } + if (nr_pages > NR_MAX_BATCHED_MIGRATION) + list_cut_before(&folios, from, &folio->lru); + else + list_splice_init(from, &folios); + rc = migrate_pages_batch(&folios, get_new_page, put_new_page, private, + mode, reason, &ret_folios, &stats); + list_splice_tail_init(&folios, &ret_folios); + if (rc < 0) { + rc_gather = rc; + goto out; + } + rc_gather += rc; + if (!list_empty(from)) + goto again; +out: /* * Put the permanent failure folio back to migration list, they * will be put back to the right list by the caller. @@ -1746,7 +1784,7 @@ out: * are migrated successfully. */ if (list_empty(from)) - rc = 0; + rc_gather = 0; count_vm_events(PGMIGRATE_SUCCESS, stats.nr_succeeded); count_vm_events(PGMIGRATE_FAIL, stats.nr_failed_pages); @@ -1760,7 +1798,7 @@ out: if (ret_succeeded) *ret_succeeded = stats.nr_succeeded; - return rc; + return rc_gather; } struct page *alloc_migration_target(struct page *page, unsigned long private) |