From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm, compaction: remove unnecessary zone parameter in some instances A zone parameter is passed into a number of top-level compaction functions despite the fact that it's already in compact_control. This is harmless but it did need an audit to check if zone actually ever changes meaningfully. This patches removes the parameter in a number of top-level functions. The change could be much deeper but this was enough to briefly clarify the flow. No functional change. Link: http://lkml.kernel.org/r/20190118175136.31341-5-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: YueHaibing <yuehaibing@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 54 ++++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 28 deletions(-) --- a/mm/compaction.c~mm-compaction-remove-unnecessary-zone-parameter-in-some-instances +++ a/mm/compaction.c @@ -1300,8 +1300,7 @@ static inline bool is_via_compact_memory return order == -1; } -static enum compact_result __compact_finished(struct zone *zone, - struct compact_control *cc) +static enum compact_result __compact_finished(struct compact_control *cc) { unsigned int order; const int migratetype = cc->migratetype; @@ -1312,7 +1311,7 @@ static enum compact_result __compact_fin /* Compaction run completes if the migrate and free scanner meet */ if (compact_scanners_met(cc)) { /* Let the next compaction start anew. */ - reset_cached_positions(zone); + reset_cached_positions(cc->zone); /* * Mark that the PG_migrate_skip information should be cleared @@ -1321,7 +1320,7 @@ static enum compact_result __compact_fin * based on an allocation request. */ if (cc->direct_compaction) - zone->compact_blockskip_flush = true; + cc->zone->compact_blockskip_flush = true; if (cc->whole_zone) return COMPACT_COMPLETE; @@ -1345,7 +1344,7 @@ static enum compact_result __compact_fin /* Direct compactor: Is a suitable page free? */ for (order = cc->order; order < MAX_ORDER; order++) { - struct free_area *area = &zone->free_area[order]; + struct free_area *area = &cc->zone->free_area[order]; bool can_steal; /* Job done if page is free of the right migratetype */ @@ -1391,13 +1390,12 @@ static enum compact_result __compact_fin return COMPACT_NO_SUITABLE_PAGE; } -static enum compact_result compact_finished(struct zone *zone, - struct compact_control *cc) +static enum compact_result compact_finished(struct compact_control *cc) { int ret; - ret = __compact_finished(zone, cc); - trace_mm_compaction_finished(zone, cc->order, ret); + ret = __compact_finished(cc); + trace_mm_compaction_finished(cc->zone, cc->order, ret); if (ret == COMPACT_NO_SUITABLE_PAGE) ret = COMPACT_CONTINUE; @@ -1524,16 +1522,16 @@ bool compaction_zonelist_suitable(struct return false; } -static enum compact_result compact_zone(struct zone *zone, struct compact_control *cc) +static enum compact_result compact_zone(struct compact_control *cc) { enum compact_result ret; - unsigned long start_pfn = zone->zone_start_pfn; - unsigned long end_pfn = zone_end_pfn(zone); + unsigned long start_pfn = cc->zone->zone_start_pfn; + unsigned long end_pfn = zone_end_pfn(cc->zone); unsigned long last_migrated_pfn; const bool sync = cc->mode != MIGRATE_ASYNC; cc->migratetype = gfpflags_to_migratetype(cc->gfp_mask); - ret = compaction_suitable(zone, cc->order, cc->alloc_flags, + ret = compaction_suitable(cc->zone, cc->order, cc->alloc_flags, cc->classzone_idx); /* Compaction is likely to fail */ if (ret == COMPACT_SUCCESS || ret == COMPACT_SKIPPED) @@ -1546,8 +1544,8 @@ static enum compact_result compact_zone( * Clear pageblock skip if there were failures recently and compaction * is about to be retried after being deferred. */ - if (compaction_restarting(zone, cc->order)) - __reset_isolation_suitable(zone); + if (compaction_restarting(cc->zone, cc->order)) + __reset_isolation_suitable(cc->zone); /* * Setup to move all movable pages to the end of the zone. Used cached @@ -1559,16 +1557,16 @@ static enum compact_result compact_zone( cc->migrate_pfn = start_pfn; cc->free_pfn = pageblock_start_pfn(end_pfn - 1); } else { - cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync]; - cc->free_pfn = zone->compact_cached_free_pfn; + cc->migrate_pfn = cc->zone->compact_cached_migrate_pfn[sync]; + cc->free_pfn = cc->zone->compact_cached_free_pfn; if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) { cc->free_pfn = pageblock_start_pfn(end_pfn - 1); - zone->compact_cached_free_pfn = cc->free_pfn; + cc->zone->compact_cached_free_pfn = cc->free_pfn; } if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) { cc->migrate_pfn = start_pfn; - zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn; - zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn; + cc->zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn; + cc->zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn; } if (cc->migrate_pfn == start_pfn) @@ -1582,11 +1580,11 @@ static enum compact_result compact_zone( migrate_prep_local(); - while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) { + while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) { int err; unsigned long start_pfn = cc->migrate_pfn; - switch (isolate_migratepages(zone, cc)) { + switch (isolate_migratepages(cc->zone, cc)) { case ISOLATE_ABORT: ret = COMPACT_CONTENDED; putback_movable_pages(&cc->migratepages); @@ -1653,7 +1651,7 @@ check_drain: if (last_migrated_pfn < current_block_start) { cpu = get_cpu(); lru_add_drain_cpu(cpu); - drain_local_pages(zone); + drain_local_pages(cc->zone); put_cpu(); /* No more flushing until we migrate again */ last_migrated_pfn = 0; @@ -1678,8 +1676,8 @@ out: * Only go back, not forward. The cached pfn might have been * already reset to zone end in compact_finished() */ - if (free_pfn > zone->compact_cached_free_pfn) - zone->compact_cached_free_pfn = free_pfn; + if (free_pfn > cc->zone->compact_cached_free_pfn) + cc->zone->compact_cached_free_pfn = free_pfn; } count_compact_events(COMPACTMIGRATE_SCANNED, cc->total_migrate_scanned); @@ -1716,7 +1714,7 @@ static enum compact_result compact_zone_ INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); - ret = compact_zone(zone, &cc); + ret = compact_zone(&cc); VM_BUG_ON(!list_empty(&cc.freepages)); VM_BUG_ON(!list_empty(&cc.migratepages)); @@ -1834,7 +1832,7 @@ static void compact_node(int nid) INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); - compact_zone(zone, &cc); + compact_zone(&cc); VM_BUG_ON(!list_empty(&cc.freepages)); VM_BUG_ON(!list_empty(&cc.migratepages)); @@ -1968,7 +1966,7 @@ static void kcompactd_do_work(pg_data_t if (kthread_should_stop()) return; - status = compact_zone(zone, &cc); + status = compact_zone(&cc); if (status == COMPACT_SUCCESS) { compaction_defer_reset(zone, cc.order, false); _
