In hot remove, we try to clear poisoned pages, but
a small optimization to check if num_poisoned_pages
is 0 helps remove the iteration through nr_pages.
Signed-off-by: Balbir Singh <bsinghar...@gmail.com>
---
mm/sparse.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/mm/sparse.c b/mm/sparse.c
index 33307fc05c4d..16219c7ddb5f 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -724,6 +724,16 @@ static void clear_hwpoisoned_pages(struct page *memmap,
int nr_pages)
if (!memmap)
return;
+ /*
+ * A further optimization is to have per section
+ * ref counted num_poisoned_pages, but that is going
+ * to need more space per memmap, for now just do
+ * a quick global check, this should speed up this
+ * routine in the absence of bad pages.
+ */
+ if (atomic_long_read(&num_poisoned_pages) == 0)
+ return;
+
for (i = 0; i < nr_pages; i++) {
if (PageHWPoison(&memmap[i])) {
atomic_long_sub(1, &num_poisoned_pages);
--
2.17.1
