mm: numa: Do not group on RO pages
And here's a little something to make sure not the whole world ends up
in a single group.
As while we don't migrate shared executable pages, we do scan/fault on
them. And since everybody links to libc, everybody ends up in the same
group.
Suggested-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-47-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/mm/memory.c b/mm/memory.c
index c57efa2..eba846b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3547,6 +3547,7 @@
int last_cpupid;
int target_nid;
bool migrated = false;
+ int flags = 0;
/*
* The "pte" at this point cannot be used safely without
@@ -3575,6 +3576,14 @@
}
BUG_ON(is_zero_pfn(page_to_pfn(page)));
+ /*
+ * Avoid grouping on DSO/COW pages in specific and RO pages
+ * in general, RO pages shouldn't hurt as much anyway since
+ * they can be in shared cache state.
+ */
+ if (!pte_write(pte))
+ flags |= TNF_NO_GROUP;
+
last_cpupid = page_cpupid_last(page);
page_nid = page_to_nid(page);
target_nid = numa_migrate_prep(page, vma, addr, page_nid);
@@ -3586,12 +3595,14 @@
/* Migrate to the requested node */
migrated = migrate_misplaced_page(page, vma, target_nid);
- if (migrated)
+ if (migrated) {
page_nid = target_nid;
+ flags |= TNF_MIGRATED;
+ }
out:
if (page_nid != -1)
- task_numa_fault(last_cpupid, page_nid, 1, migrated);
+ task_numa_fault(last_cpupid, page_nid, 1, flags);
return 0;
}
@@ -3632,6 +3643,7 @@
int page_nid = -1;
int target_nid;
bool migrated = false;
+ int flags = 0;
if (!pte_present(pteval))
continue;
@@ -3651,20 +3663,30 @@
if (unlikely(!page))
continue;
+ /*
+ * Avoid grouping on DSO/COW pages in specific and RO pages
+ * in general, RO pages shouldn't hurt as much anyway since
+ * they can be in shared cache state.
+ */
+ if (!pte_write(pteval))
+ flags |= TNF_NO_GROUP;
+
last_cpupid = page_cpupid_last(page);
page_nid = page_to_nid(page);
target_nid = numa_migrate_prep(page, vma, addr, page_nid);
pte_unmap_unlock(pte, ptl);
if (target_nid != -1) {
migrated = migrate_misplaced_page(page, vma, target_nid);
- if (migrated)
+ if (migrated) {
page_nid = target_nid;
+ flags |= TNF_MIGRATED;
+ }
} else {
put_page(page);
}
if (page_nid != -1)
- task_numa_fault(last_cpupid, page_nid, 1, migrated);
+ task_numa_fault(last_cpupid, page_nid, 1, flags);
pte = pte_offset_map_lock(mm, pmdp, addr, &ptl);
}