openwrt/target/linux/bcm27xx/patches-6.6/950-1261-mm-vmscan-Maintain-TLB-coherency-in-LRU-code.patch
Álvaro Fernández Rojas 538a1d740c bcm27xx: update to latest RPi patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.58..rpi-6.6.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-10-31 13:44:23 +01:00

28 lines
957 B
Diff

From 536f2097dc397e4ebd0566e8f00219c02d7c8073 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
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 <phil@raspberrypi.com>
---
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++;