From 536f2097dc397e4ebd0566e8f00219c02d7c8073 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Thu, 12 Sep 2024 10:06:50 +0100 Subject: [PATCH 1261/1350] mm/vmscan: Maintain TLB coherency in LRU code As a workaround (and possibly a fix) for CPU spins observed on BCM2837, use ptep_clear_flush_young instead of ptep_test_and_clear_young inside lru_gen_look_around in order to expose PTE changes to the MMU. Note that on architectures that don't require an explicit flush, ptep_clear_flush_young just calls ptep_test_and_clear_young. Signed-off-by: Phil Elwell --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4716,7 +4716,7 @@ void lru_gen_look_around(struct page_vma if (!folio) continue; - if (!ptep_test_and_clear_young(vma, addr, pte + i)) + if (!ptep_clear_flush_young(vma, addr, pte + i)) VM_WARN_ON_ONCE(true); young++;