From a21d2133215b58fbf254ea2bb77eb3143ffedf60 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Fri, 3 Mar 2023 11:01:54 +0800 Subject: migrate_pages: move split folios processing out of migrate_pages_batch() To simplify the code logic and reduce the line number. Link: https://lkml.kernel.org/r/20230303030155.160983-3-ying.huang@intel.com Fixes: 5dfab109d519 ("migrate_pages: batch _unmap and _move") Signed-off-by: "Huang, Ying" Reviewed-by: Baolin Wang Cc: Hugh Dickins Cc: "Xu, Pengfei" Cc: Christoph Hellwig Cc: Stefan Roesch Cc: Tejun Heo Cc: Xin Hao Cc: Zi Yan Cc: Yang Shi Cc: Matthew Wilcox Cc: Mike Kravetz Signed-off-by: Andrew Morton --- mm/migrate.c | 78 ++++++++++++++++++++++-------------------------------------- 1 file changed, 28 insertions(+), 50 deletions(-) (limited to 'mm') diff --git a/mm/migrate.c b/mm/migrate.c index f348e0a7b1df..b61abe529107 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1616,9 +1616,10 @@ static int migrate_hugetlbs(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, struct list_head *ret_folios, - struct migrate_pages_stats *stats) + struct list_head *split_folios, struct migrate_pages_stats *stats, + int nr_pass) { - int retry; + int retry = 1; int large_retry = 1; int thp_retry = 1; int nr_failed = 0; @@ -1628,21 +1629,15 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, bool is_large = false; bool is_thp = false; struct folio *folio, *folio2, *dst = NULL, *dst2; - int rc, rc_saved, nr_pages; - LIST_HEAD(split_folios); + int rc, rc_saved = 0, nr_pages; LIST_HEAD(unmap_folios); LIST_HEAD(dst_folios); bool nosplit = (reason == MR_NUMA_MISPLACED); - bool no_split_folio_counting = false; VM_WARN_ON_ONCE(mode != MIGRATE_ASYNC && !list_empty(from) && !list_is_singular(from)); -retry: - rc_saved = 0; - retry = 1; - for (pass = 0; - pass < NR_MAX_MIGRATE_PAGES_RETRY && (retry || large_retry); - pass++) { + + for (pass = 0; pass < nr_pass && (retry || large_retry); pass++) { retry = 0; large_retry = 0; thp_retry = 0; @@ -1673,7 +1668,7 @@ retry: if (!thp_migration_supported() && is_thp) { nr_large_failed++; stats->nr_thp_failed++; - if (!try_split_folio(folio, &split_folios)) { + if (!try_split_folio(folio, split_folios)) { stats->nr_thp_split++; continue; } @@ -1705,7 +1700,7 @@ retry: 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); + int ret = try_split_folio(folio, split_folios); if (!ret) { stats->nr_thp_split += is_thp; @@ -1722,18 +1717,11 @@ retry: break; } } - } else if (!no_split_folio_counting) { + } else { nr_failed++; } 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 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, ret_folios); /* nr_failed isn't updated for not used */ nr_large_failed += large_retry; stats->nr_thp_failed += thp_retry; @@ -1746,7 +1734,7 @@ retry: if (is_large) { large_retry++; thp_retry += is_thp; - } else if (!no_split_folio_counting) { + } else { retry++; } nr_retry_pages += nr_pages; @@ -1769,7 +1757,7 @@ retry: if (is_large) { nr_large_failed++; stats->nr_thp_failed += is_thp; - } else if (!no_split_folio_counting) { + } else { nr_failed++; } @@ -1787,9 +1775,7 @@ move: try_to_unmap_flush(); retry = 1; - for (pass = 0; - pass < NR_MAX_MIGRATE_PAGES_RETRY && (retry || large_retry); - pass++) { + for (pass = 0; pass < nr_pass && (retry || large_retry); pass++) { retry = 0; large_retry = 0; thp_retry = 0; @@ -1818,7 +1804,7 @@ move: if (is_large) { large_retry++; thp_retry += is_thp; - } else if (!no_split_folio_counting) { + } else { retry++; } nr_retry_pages += nr_pages; @@ -1831,7 +1817,7 @@ move: if (is_large) { nr_large_failed++; stats->nr_thp_failed += is_thp; - } else if (!no_split_folio_counting) { + } else { nr_failed++; } @@ -1868,27 +1854,6 @@ out: dst2 = list_next_entry(dst, lru); } - /* - * Try to migrate split folios of fail-to-migrate large folios, no - * nr_failed counting in this round, since all split folios of a - * large folio is counted as 1 failure in the first round. - */ - if (rc >= 0 && !list_empty(&split_folios)) { - /* - * 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(&split_folios, from); - /* - * Force async mode to avoid to wait lock or bit when we have - * locked more than one folios. - */ - mode = MIGRATE_ASYNC; - no_split_folio_counting = true; - goto retry; - } - return rc; } @@ -1927,6 +1892,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, struct folio *folio, *folio2; LIST_HEAD(folios); LIST_HEAD(ret_folios); + LIST_HEAD(split_folios); struct migrate_pages_stats stats; trace_mm_migrate_pages_start(mode, reason); @@ -1960,12 +1926,24 @@ again: else list_splice_init(from, &folios); rc = migrate_pages_batch(&folios, get_new_page, put_new_page, private, - mode, reason, &ret_folios, &stats); + mode, reason, &ret_folios, &split_folios, &stats, + NR_MAX_MIGRATE_PAGES_RETRY); list_splice_tail_init(&folios, &ret_folios); if (rc < 0) { rc_gather = rc; + list_splice_tail(&split_folios, &ret_folios); goto out; } + if (!list_empty(&split_folios)) { + /* + * Failure isn't counted since all split folios of a large folio + * is counted as 1 failure already. And, we only try to migrate + * with minimal effort, force MIGRATE_ASYNC mode and retry once. + */ + migrate_pages_batch(&split_folios, get_new_page, put_new_page, private, + MIGRATE_ASYNC, reason, &ret_folios, NULL, &stats, 1); + list_splice_tail_init(&split_folios, &ret_folios); + } rc_gather += rc; if (!list_empty(from)) goto again; -- cgit v1.2.3