diff options
| -rw-r--r-- | mm/compaction.c | 52 | ||||
| -rw-r--r-- | mm/internal.h | 10 | ||||
| -rw-r--r-- | mm/page_alloc.c | 7 |
3 files changed, 36 insertions, 33 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index e04f4476e68e..c4d8007221b7 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -787,15 +787,14 @@ static bool too_many_isolated(pg_data_t *pgdat) * * Isolate all pages that can be migrated from the range specified by * [low_pfn, end_pfn). The range is expected to be within same pageblock. - * Returns zero if there is a fatal signal pending, otherwise PFN of the - * first page that was not scanned (which may be both less, equal to or more - * than end_pfn). + * Returns errno, like -EAGAIN or -EINTR in case e.g signal pending or congestion, + * or 0. + * cc->migrate_pfn will contain the next pfn to scan. * * The pages are isolated on cc->migratepages list (not required to be empty), - * and cc->nr_migratepages is updated accordingly. The cc->migrate_pfn field - * is neither read nor updated. + * and cc->nr_migratepages is updated accordingly. */ -static unsigned long +static int isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, unsigned long end_pfn, isolate_mode_t isolate_mode) { @@ -809,6 +808,9 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, bool skip_on_failure = false; unsigned long next_skip_pfn = 0; bool skip_updated = false; + int ret = 0; + + cc->migrate_pfn = low_pfn; /* * Ensure that there are not too many pages isolated from the LRU @@ -818,16 +820,16 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, while (unlikely(too_many_isolated(pgdat))) { /* stop isolation if there are still pages not migrated */ if (cc->nr_migratepages) - return 0; + return -EAGAIN; /* async migration should just abort */ if (cc->mode == MIGRATE_ASYNC) - return 0; + return -EAGAIN; congestion_wait(BLK_RW_ASYNC, HZ/10); if (fatal_signal_pending(current)) - return 0; + return -EINTR; } cond_resched(); @@ -875,8 +877,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (fatal_signal_pending(current)) { cc->contended = true; + ret = -EINTR; - low_pfn = 0; goto fatal_pending; } @@ -1130,7 +1132,9 @@ fatal_pending: if (nr_isolated) count_compact_events(COMPACTISOLATED, nr_isolated); - return low_pfn; + cc->migrate_pfn = low_pfn; + + return ret; } /** @@ -1139,15 +1143,14 @@ fatal_pending: * @start_pfn: The first PFN to start isolating. * @end_pfn: The one-past-last PFN. * - * Returns zero if isolation fails fatally due to e.g. pending signal. - * Otherwise, function returns one-past-the-last PFN of isolated page - * (which may be greater than end_pfn if end fell in a middle of a THP page). + * Returns -EAGAIN when contented, -EINTR in case of a signal pending or 0. */ -unsigned long +int isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn, block_start_pfn, block_end_pfn; + int ret = 0; /* Scan block by block. First and last block may be incomplete */ pfn = start_pfn; @@ -1166,17 +1169,17 @@ isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn, block_end_pfn, cc->zone)) continue; - pfn = isolate_migratepages_block(cc, pfn, block_end_pfn, - ISOLATE_UNEVICTABLE); + ret = isolate_migratepages_block(cc, pfn, block_end_pfn, + ISOLATE_UNEVICTABLE); - if (!pfn) + if (ret) break; if (cc->nr_migratepages >= COMPACT_CLUSTER_MAX) break; } - return pfn; + return ret; } #endif /* CONFIG_COMPACTION || CONFIG_CMA */ @@ -1847,7 +1850,7 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) */ for (; block_end_pfn <= cc->free_pfn; fast_find_block = false, - low_pfn = block_end_pfn, + cc->migrate_pfn = low_pfn = block_end_pfn, block_start_pfn = block_end_pfn, block_end_pfn += pageblock_nr_pages) { @@ -1889,10 +1892,8 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) } /* Perform the isolation */ - low_pfn = isolate_migratepages_block(cc, low_pfn, - block_end_pfn, isolate_mode); - - if (!low_pfn) + if (isolate_migratepages_block(cc, low_pfn, block_end_pfn, + isolate_mode)) return ISOLATE_ABORT; /* @@ -1903,9 +1904,6 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) break; } - /* Record where migration scanner will be restarted. */ - cc->migrate_pfn = low_pfn; - return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE; } diff --git a/mm/internal.h b/mm/internal.h index ef5f336f59bd..feeaaf06705d 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -244,7 +244,13 @@ struct compact_control { unsigned int nr_freepages; /* Number of isolated free pages */ unsigned int nr_migratepages; /* Number of pages to migrate */ unsigned long free_pfn; /* isolate_freepages search base */ - unsigned long migrate_pfn; /* isolate_migratepages search base */ + /* + * Acts as an in/out parameter to page isolation for migration. + * isolate_migratepages uses it as a search base. + * isolate_migratepages_block will update the value to the next pfn + * after the last isolated one. + */ + unsigned long migrate_pfn; unsigned long fast_start_pfn; /* a pfn to start linear scan from */ struct zone *zone; unsigned long total_migrate_scanned; @@ -280,7 +286,7 @@ struct capture_control { unsigned long isolate_freepages_range(struct compact_control *cc, unsigned long start_pfn, unsigned long end_pfn); -unsigned long +int isolate_migratepages_range(struct compact_control *cc, unsigned long low_pfn, unsigned long end_pfn); int find_suitable_fallback(struct free_area *area, unsigned int order, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d9acd86fa761..656f86a98554 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8689,11 +8689,10 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, if (list_empty(&cc->migratepages)) { cc->nr_migratepages = 0; - pfn = isolate_migratepages_range(cc, pfn, end); - if (!pfn) { - ret = -EINTR; + ret = isolate_migratepages_range(cc, pfn, end); + if (ret && ret != -EAGAIN) break; - } + pfn = cc->migrate_pfn; tries = 0; } else if (++tries == 5) { ret = -EBUSY; |