On 4/27/22 10:08 AM, Yu Zhao wrote:
On Tue, Apr 26, 2022 at 10:33 PM Aneesh Kumar K.V
<aneesh.kumar@xxxxxxxxxxxxx> wrote:
Yu Zhao <yuzhao@xxxxxxxxxx> writes:
....
diff --git a/mm/rmap.c b/mm/rmap.c
index fedb82371efe..7cb7ef29088a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -73,6 +73,7 @@
#include <linux/page_idle.h>
#include <linux/memremap.h>
#include <linux/userfaultfd_k.h>
+#include <linux/mm_inline.h>
#include <asm/tlbflush.h>
@@ -821,6 +822,12 @@ static bool folio_referenced_one(struct folio *folio,
}
if (pvmw.pte) {
+ if (lru_gen_enabled() && pte_young(*pvmw.pte) &&
+ !(vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))) {
+ lru_gen_look_around(&pvmw);
+ referenced++;
+ }
Is it required to update referenced here? we do that below after
clearing the young bit. Or is the goal to identify whether we found any
young pte around?
referenced++ is needed because lru_gen_look_around() also clears the
young bit in pvmw.pte. And ptep_clear_flush_young_notify() will return
false unless mmu notifier returns true.
should we then use a mmu notifier variant of clear_young in
lru_gen_look_around() ?
-aneesh
