[PATCH 03/16] mm: numa: Account for THP numa hinting faults on the correct node

Mel Gorman
2013-07-11T09:51:17Z

THP NUMA hinting fault on pages that are not migrated are being
accounted for incorrectly. Currently the fault will be counted as if the
task was running on a node local to the page which is not necessarily
true.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/huge_memory.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e2f7f5aa..e4a79fa 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1293,7 +1293,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page;
unsigned long haddr = addr & HPAGE_PMD_MASK;
int target_nid;
- int current_nid = -1;
+ int src_nid = -1;
bool migrated;

spin_lock(&mm->page_table_lock);
@@ -1302,9 +1302,9 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,

page = pmd_page(pmd);
get_page(page);
- current_nid = page_to_nid(page);
+ src_nid = numa_node_id();
count_vm_numa_event(NUMA_HINT_FAULTS);
- if (current_nid == numa_node_id())
+ if (src_nid == page_to_nid(page))
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);

target_nid = mpol_misplaced(page, vma, haddr);
@@ -1346,8 +1346,8 @@ clear_pmdnuma:
update_mmu_cache_pmd(vma, addr, pmdp);
out_unlock:
spin_unlock(&mm->page_table_lock);
- if (current_nid != -1)
- task_numa_fault(current_nid, HPAGE_PMD_NR, false);
+ if (src_nid != -1)
+ task_numa_fault(src_nid, HPAGE_PMD_NR, false);
return 0;
}

--
1.8.1.4