mm, compaction: terminate async compaction when rescheduling
[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / compaction.c
index d4a4ee8..4d38c85 100644 (file)
@@ -89,7 +89,8 @@ static void __reset_isolation_suitable(struct zone *zone)
        unsigned long end_pfn = zone_end_pfn(zone);
        unsigned long pfn;
 
-       zone->compact_cached_migrate_pfn = start_pfn;
+       zone->compact_cached_migrate_pfn[0] = start_pfn;
+       zone->compact_cached_migrate_pfn[1] = start_pfn;
        zone->compact_cached_free_pfn = end_pfn;
        zone->compact_blockskip_flush = false;
 
@@ -131,9 +132,10 @@ void reset_isolation_suitable(pg_data_t *pgdat)
  */
 static void update_pageblock_skip(struct compact_control *cc,
                        struct page *page, unsigned long nr_isolated,
-                       bool migrate_scanner)
+                       bool set_unsuitable, bool migrate_scanner)
 {
        struct zone *zone = cc->zone;
+       unsigned long pfn;
 
        if (cc->ignore_skip_hint)
                return;
@@ -141,20 +143,32 @@ static void update_pageblock_skip(struct compact_control *cc,
        if (!page)
                return;
 
-       if (!nr_isolated) {
-               unsigned long pfn = page_to_pfn(page);
+       if (nr_isolated)
+               return;
+
+       /*
+        * Only skip pageblocks when all forms of compaction will be known to
+        * fail in the near future.
+        */
+       if (set_unsuitable)
                set_pageblock_skip(page);
 
-               /* Update where compaction should restart */
-               if (migrate_scanner) {
-                       if (!cc->finished_update_migrate &&
-                           pfn > zone->compact_cached_migrate_pfn)
-                               zone->compact_cached_migrate_pfn = pfn;
-               } else {
-                       if (!cc->finished_update_free &&
-                           pfn < zone->compact_cached_free_pfn)
-                               zone->compact_cached_free_pfn = pfn;
-               }
+       pfn = page_to_pfn(page);
+
+       /* Update where async and sync compaction should restart */
+       if (migrate_scanner) {
+               if (cc->finished_update_migrate)
+                       return;
+               if (pfn > zone->compact_cached_migrate_pfn[0])
+                       zone->compact_cached_migrate_pfn[0] = pfn;
+               if (cc->mode != MIGRATE_ASYNC &&
+                   pfn > zone->compact_cached_migrate_pfn[1])
+                       zone->compact_cached_migrate_pfn[1] = pfn;
+       } else {
+               if (cc->finished_update_free)
+                       return;
+               if (pfn < zone->compact_cached_free_pfn)
+                       zone->compact_cached_free_pfn = pfn;
        }
 }
 #else
@@ -166,7 +180,7 @@ static inline bool isolation_suitable(struct compact_control *cc,
 
 static void update_pageblock_skip(struct compact_control *cc,
                        struct page *page, unsigned long nr_isolated,
-                       bool migrate_scanner)
+                       bool set_unsuitable, bool migrate_scanner)
 {
 }
 #endif /* CONFIG_COMPACTION */
@@ -195,7 +209,7 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags,
                }
 
                /* async aborts if taking too long or contended */
-               if (!cc->sync) {
+               if (cc->mode == MIGRATE_ASYNC) {
                        cc->contended = true;
                        return false;
                }
@@ -323,7 +337,8 @@ isolate_fail:
 
        /* Update the pageblock-skip if the whole pageblock was scanned */
        if (blockpfn == end_pfn)
-               update_pageblock_skip(cc, valid_page, total_isolated, false);
+               update_pageblock_skip(cc, valid_page, total_isolated, true,
+                                     false);
 
        count_compact_events(COMPACTFREE_SCANNED, nr_scanned);
        if (total_isolated)
@@ -458,8 +473,9 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
        unsigned long flags;
        bool locked = false;
        struct page *page = NULL, *valid_page = NULL;
-       bool skipped_async_unsuitable = false;
-       const isolate_mode_t mode = (!cc->sync ? ISOLATE_ASYNC_MIGRATE : 0) |
+       bool set_unsuitable = true;
+       const isolate_mode_t mode = (cc->mode == MIGRATE_ASYNC ?
+                                       ISOLATE_ASYNC_MIGRATE : 0) |
                                    (unevictable ? ISOLATE_UNEVICTABLE : 0);
 
        /*
@@ -469,7 +485,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
         */
        while (unlikely(too_many_isolated(zone))) {
                /* async migration should just abort */
-               if (!cc->sync)
+               if (cc->mode == MIGRATE_ASYNC)
                        return 0;
 
                congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -478,8 +494,13 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
                        return 0;
        }
 
+       if (cond_resched()) {
+               /* Async terminates prematurely on need_resched() */
+               if (cc->mode == MIGRATE_ASYNC)
+                       return 0;
+       }
+
        /* Time to isolate some pages for migration */
-       cond_resched();
        for (; low_pfn < end_pfn; low_pfn++) {
                /* give a chance to irqs before checking need_resched() */
                if (locked && !(low_pfn % SWAP_CLUSTER_MAX)) {
@@ -534,9 +555,9 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
                         * the minimum amount of work satisfies the allocation
                         */
                        mt = get_pageblock_migratetype(page);
-                       if (!cc->sync && !migrate_async_suitable(mt)) {
-                               cc->finished_update_migrate = true;
-                               skipped_async_unsuitable = true;
+                       if (cc->mode == MIGRATE_ASYNC &&
+                           !migrate_async_suitable(mt)) {
+                               set_unsuitable = false;
                                goto next_pageblock;
                        }
                }
@@ -640,11 +661,10 @@ next_pageblock:
        /*
         * Update the pageblock-skip information and cached scanner pfn,
         * if the whole pageblock was scanned without isolating any page.
-        * This is not done when pageblock was skipped due to being unsuitable
-        * for async compaction, so that eventual sync compaction can try.
         */
-       if (low_pfn == end_pfn && !skipped_async_unsuitable)
-               update_pageblock_skip(cc, valid_page, nr_isolated, true);
+       if (low_pfn == end_pfn)
+               update_pageblock_skip(cc, valid_page, nr_isolated,
+                                     set_unsuitable, true);
 
        trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
 
@@ -665,7 +685,10 @@ static void isolate_freepages(struct zone *zone,
                                struct compact_control *cc)
 {
        struct page *page;
-       unsigned long high_pfn, low_pfn, pfn, z_end_pfn;
+       unsigned long block_start_pfn;  /* start of current pageblock */
+       unsigned long block_end_pfn;    /* end of current pageblock */
+       unsigned long low_pfn;       /* lowest pfn scanner is able to scan */
+       unsigned long next_free_pfn; /* start pfn for scaning at next round */
        int nr_freepages = cc->nr_freepages;
        struct list_head *freelist = &cc->freepages;
 
@@ -673,32 +696,33 @@ static void isolate_freepages(struct zone *zone,
         * Initialise the free scanner. The starting point is where we last
         * successfully isolated from, zone-cached value, or the end of the
         * zone when isolating for the first time. We need this aligned to
-        * the pageblock boundary, because we do pfn -= pageblock_nr_pages
-        * in the for loop.
+        * the pageblock boundary, because we do
+        * block_start_pfn -= pageblock_nr_pages in the for loop.
+        * For ending point, take care when isolating in last pageblock of a
+        * a zone which ends in the middle of a pageblock.
         * The low boundary is the end of the pageblock the migration scanner
         * is using.
         */
-       pfn = cc->free_pfn & ~(pageblock_nr_pages-1);
+       block_start_pfn = cc->free_pfn & ~(pageblock_nr_pages-1);
+       block_end_pfn = min(block_start_pfn + pageblock_nr_pages,
+                                               zone_end_pfn(zone));
        low_pfn = ALIGN(cc->migrate_pfn + 1, pageblock_nr_pages);
 
        /*
-        * Take care that if the migration scanner is at the end of the zone
-        * that the free scanner does not accidentally move to the next zone
-        * in the next isolation cycle.
+        * If no pages are isolated, the block_start_pfn < low_pfn check
+        * will kick in.
         */
-       high_pfn = min(low_pfn, pfn);
-
-       z_end_pfn = zone_end_pfn(zone);
+       next_free_pfn = 0;
 
        /*
         * Isolate free pages until enough are available to migrate the
         * pages on cc->migratepages. We stop searching if the migrate
         * and free page scanners meet or enough free pages are isolated.
         */
-       for (; pfn >= low_pfn && cc->nr_migratepages > nr_freepages;
-                                       pfn -= pageblock_nr_pages) {
+       for (; block_start_pfn >= low_pfn && cc->nr_migratepages > nr_freepages;
+                               block_end_pfn = block_start_pfn,
+                               block_start_pfn -= pageblock_nr_pages) {
                unsigned long isolated;
-               unsigned long end_pfn;
 
                /*
                 * This can iterate a massively long zone without finding any
@@ -707,7 +731,7 @@ static void isolate_freepages(struct zone *zone,
                 */
                cond_resched();
 
-               if (!pfn_valid(pfn))
+               if (!pfn_valid(block_start_pfn))
                        continue;
 
                /*
@@ -717,7 +741,7 @@ static void isolate_freepages(struct zone *zone,
                 * i.e. it's possible that all pages within a zones range of
                 * pages do not belong to a single zone.
                 */
-               page = pfn_to_page(pfn);
+               page = pfn_to_page(block_start_pfn);
                if (page_zone(page) != zone)
                        continue;
 
@@ -730,14 +754,8 @@ static void isolate_freepages(struct zone *zone,
                        continue;
 
                /* Found a block suitable for isolating free pages from */
-
-               /*
-                * Take care when isolating in last pageblock of a zone which
-                * ends in the middle of a pageblock.
-                */
-               end_pfn = min(pfn + pageblock_nr_pages, z_end_pfn);
-               isolated = isolate_freepages_block(cc, pfn, end_pfn,
-                                                  freelist, false);
+               isolated = isolate_freepages_block(cc, block_start_pfn,
+                                       block_end_pfn, freelist, false);
                nr_freepages += isolated;
 
                /*
@@ -745,9 +763,9 @@ static void isolate_freepages(struct zone *zone,
                 * looking for free pages, the search will restart here as
                 * page migration may have returned some pages to the allocator
                 */
-               if (isolated) {
+               if (isolated && next_free_pfn == 0) {
                        cc->finished_update_free = true;
-                       high_pfn = max(high_pfn, pfn);
+                       next_free_pfn = block_start_pfn;
                }
        }
 
@@ -758,10 +776,10 @@ static void isolate_freepages(struct zone *zone,
         * If we crossed the migrate scanner, we want to keep it that way
         * so that compact_finished() may detect this
         */
-       if (pfn < low_pfn)
-               cc->free_pfn = max(pfn, zone->zone_start_pfn);
-       else
-               cc->free_pfn = high_pfn;
+       if (block_start_pfn < low_pfn)
+               next_free_pfn = cc->migrate_pfn;
+
+       cc->free_pfn = next_free_pfn;
        cc->nr_freepages = nr_freepages;
 }
 
@@ -792,23 +810,32 @@ static struct page *compaction_alloc(struct page *migratepage,
 }
 
 /*
- * We cannot control nr_migratepages and nr_freepages fully when migration is
- * running as migrate_pages() has no knowledge of compact_control. When
- * migration is complete, we count the number of pages on the lists by hand.
+ * This is a migrate-callback that "frees" freepages back to the isolated
+ * freelist.  All pages on the freelist are from the same zone, so there is no
+ * special handling needed for NUMA.
+ */
+static void compaction_free(struct page *page, unsigned long data)
+{
+       struct compact_control *cc = (struct compact_control *)data;
+
+       list_add(&page->lru, &cc->freepages);
+       cc->nr_freepages++;
+}
+
+/*
+ * We cannot control nr_migratepages fully when migration is running as
+ * migrate_pages() has no knowledge of of compact_control.  When migration is
+ * complete, we count the number of pages on the list by hand.
  */
 static void update_nr_listpages(struct compact_control *cc)
 {
        int nr_migratepages = 0;
-       int nr_freepages = 0;
        struct page *page;
 
        list_for_each_entry(page, &cc->migratepages, lru)
                nr_migratepages++;
-       list_for_each_entry(page, &cc->freepages, lru)
-               nr_freepages++;
 
        cc->nr_migratepages = nr_migratepages;
-       cc->nr_freepages = nr_freepages;
 }
 
 /* possible outcome of isolate_migratepages */
@@ -861,7 +888,8 @@ static int compact_finished(struct zone *zone,
        /* Compaction run completes if the migrate and free scanner meet */
        if (cc->free_pfn <= cc->migrate_pfn) {
                /* Let the next compaction start anew. */
-               zone->compact_cached_migrate_pfn = zone->zone_start_pfn;
+               zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
+               zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
                zone->compact_cached_free_pfn = zone_end_pfn(zone);
 
                /*
@@ -961,6 +989,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
        int ret;
        unsigned long start_pfn = zone->zone_start_pfn;
        unsigned long end_pfn = zone_end_pfn(zone);
+       const bool sync = cc->mode != MIGRATE_ASYNC;
 
        ret = compaction_suitable(zone, cc->order);
        switch (ret) {
@@ -986,7 +1015,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
         * information on where the scanners should start but check that it
         * is initialised by ensuring the values are within zone boundaries.
         */
-       cc->migrate_pfn = zone->compact_cached_migrate_pfn;
+       cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
        cc->free_pfn = zone->compact_cached_free_pfn;
        if (cc->free_pfn < start_pfn || cc->free_pfn > end_pfn) {
                cc->free_pfn = end_pfn & ~(pageblock_nr_pages-1);
@@ -994,7 +1023,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
        }
        if (cc->migrate_pfn < start_pfn || cc->migrate_pfn > end_pfn) {
                cc->migrate_pfn = start_pfn;
-               zone->compact_cached_migrate_pfn = cc->migrate_pfn;
+               zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
+               zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
        }
 
        trace_mm_compaction_begin(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn);
@@ -1019,8 +1049,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
 
                nr_migrate = cc->nr_migratepages;
                err = migrate_pages(&cc->migratepages, compaction_alloc,
-                               (unsigned long)cc,
-                               cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC,
+                               compaction_free, (unsigned long)cc, cc->mode,
                                MR_COMPACTION);
                update_nr_listpages(cc);
                nr_remaining = cc->nr_migratepages;
@@ -1053,9 +1082,8 @@ out:
        return ret;
 }
 
-static unsigned long compact_zone_order(struct zone *zone,
-                                int order, gfp_t gfp_mask,
-                                bool sync, bool *contended)
+static unsigned long compact_zone_order(struct zone *zone, int order,
+               gfp_t gfp_mask, enum migrate_mode mode, bool *contended)
 {
        unsigned long ret;
        struct compact_control cc = {
@@ -1064,7 +1092,7 @@ static unsigned long compact_zone_order(struct zone *zone,
                .order = order,
                .migratetype = allocflags_to_migratetype(gfp_mask),
                .zone = zone,
-               .sync = sync,
+               .mode = mode,
        };
        INIT_LIST_HEAD(&cc.freepages);
        INIT_LIST_HEAD(&cc.migratepages);
@@ -1086,7 +1114,7 @@ int sysctl_extfrag_threshold = 500;
  * @order: The order of the current allocation
  * @gfp_mask: The GFP mask of the current allocation
  * @nodemask: The allowed nodes to allocate from
- * @sync: Whether migration is synchronous or not
+ * @mode: The migration mode for async, sync light, or sync migration
  * @contended: Return value that is true if compaction was aborted due to lock contention
  * @page: Optionally capture a free page of the requested order during compaction
  *
@@ -1094,7 +1122,7 @@ int sysctl_extfrag_threshold = 500;
  */
 unsigned long try_to_compact_pages(struct zonelist *zonelist,
                        int order, gfp_t gfp_mask, nodemask_t *nodemask,
-                       bool sync, bool *contended)
+                       enum migrate_mode mode, bool *contended)
 {
        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
        int may_enter_fs = gfp_mask & __GFP_FS;
@@ -1119,7 +1147,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
                                                                nodemask) {
                int status;
 
-               status = compact_zone_order(zone, order, gfp_mask, sync,
+               status = compact_zone_order(zone, order, gfp_mask, mode,
                                                contended);
                rc = max(status, rc);
 
@@ -1169,7 +1197,7 @@ void compact_pgdat(pg_data_t *pgdat, int order)
 {
        struct compact_control cc = {
                .order = order,
-               .sync = false,
+               .mode = MIGRATE_ASYNC,
        };
 
        if (!order)
@@ -1182,7 +1210,7 @@ static void compact_node(int nid)
 {
        struct compact_control cc = {
                .order = -1,
-               .sync = true,
+               .mode = MIGRATE_SYNC,
                .ignore_skip_hint = true,
        };