Hugh pointed out some issues that needed addressing in the THP native
migration patch

o transhuge isolations should be accounted as HPAGE_PMD_NR, not 1
o the migratepages list is doing nothing and is garbage leftover
  from an attempt to mesh transhuge migration properly with normal
  migration. Looking again now, I think it would trigger errors if list
  debugging was enabled and the THP migration failed. When I had a bunch
  of debugging options set earlier in development, list debugging was not
  one of them. This potentially could take a long time to hit but if you
  see bugs that look like LRU list corruption then this could be it.

Additionally

o Account for transhuage pages that are migrated so we know roughly
  how many MB/sec are being migrated for a given workload.

Signed-off-by: Mel Gorman <mgor...@suse.de>
---
 mm/migrate.c |   18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index d7c5bdf..b84fded 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1532,7 +1532,12 @@ int numamigrate_isolate_page(pg_data_t *pgdat, struct 
page *page)
                put_page(page);
 
                page_lru = page_is_file_cache(page);
-               inc_zone_page_state(page, NR_ISOLATED_ANON + page_lru);
+               if (!PageTransHuge(page))
+                       inc_zone_page_state(page, NR_ISOLATED_ANON + page_lru);
+               else
+                       mod_zone_page_state(page_zone(page),
+                                       NR_ISOLATED_ANON + page_lru,
+                                       HPAGE_PMD_NR);
        }
 
        return 1;
@@ -1598,7 +1603,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
        unsigned long haddr = address & HPAGE_PMD_MASK;
        pg_data_t *pgdat = NODE_DATA(node);
        int isolated = 0;
-       LIST_HEAD(migratepages);
        struct page *new_page = NULL;
        struct mem_cgroup *memcg = NULL;
        int page_lru = page_is_file_cache(page);
@@ -1626,7 +1630,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
        isolated = numamigrate_isolate_page(pgdat, page);
        if (!isolated)
                goto out_keep_locked;
-       list_add(&page->lru, &migratepages);
 
        /* Prepare a page as a migration target */
        __set_page_locked(new_page);
@@ -1655,6 +1658,8 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 
                unlock_page(page);
                putback_lru_page(page);
+
+               count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
                goto out;
        }
 
@@ -1690,8 +1695,13 @@ int migrate_misplaced_transhuge_page(struct mm_struct 
*mm,
        put_page(page);                 /* Drop the rmap reference */
        put_page(page);                 /* Drop the LRU isolation reference */
 
+       count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR);
+       count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR);
+
 out:
-       dec_zone_page_state(page, NR_ISOLATED_ANON + page_lru);
+       mod_zone_page_state(page_zone(page),
+                       NR_ISOLATED_ANON + page_lru,
+                       -HPAGE_PMD_NR);
        return isolated;
 
 out_dropref:
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to