target/linux/generic/backport-6.1/020-v6.3-08-UPSTREAM-mm-multi-gen-LRU-simplify-arch_has_hw_pte_y.patch

   1 From 25887d48dff860751a06caa4188bfaf6bfb6e4b2 Mon Sep 17 00:00:00 2001
   2 From: Yu Zhao <yuzhao@google.com>
   3 Date: Wed, 21 Dec 2022 21:19:06 -0700
   4 Subject: [PATCH 08/19] UPSTREAM: mm: multi-gen LRU: simplify
   5  arch_has_hw_pte_young() check
   6
   7 Scanning page tables when hardware does not set the accessed bit has
   8 no real use cases.
   9
  10 Link: https://lkml.kernel.org/r/20221222041905.2431096-9-yuzhao@google.com
  11 Signed-off-by: Yu Zhao <yuzhao@google.com>
  12 Cc: Johannes Weiner <hannes@cmpxchg.org>
  13 Cc: Jonathan Corbet <corbet@lwn.net>
  14 Cc: Michael Larabel <Michael@MichaelLarabel.com>
  15 Cc: Michal Hocko <mhocko@kernel.org>
  16 Cc: Mike Rapoport <rppt@kernel.org>
  17 Cc: Roman Gushchin <roman.gushchin@linux.dev>
  18 Cc: Suren Baghdasaryan <surenb@google.com>
  19 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  20 Bug: 274865848
  21 (cherry picked from commit f386e9314025ea99dae639ed2032560a92081430)
  22 Change-Id: I84d97ab665b4e3bb862a9bc7d72f50dea7191a6b
  23 Signed-off-by: T.J. Mercier <tjmercier@google.com>
  24 ---
  25  mm/vmscan.c | 2 +-
  26  1 file changed, 1 insertion(+), 1 deletion(-)
  27
  28 --- a/mm/vmscan.c
  29 +++ b/mm/vmscan.c
  30 @@ -4417,7 +4417,7 @@ static bool try_to_inc_max_seq(struct lr
  31          * handful of PTEs. Spreading the work out over a period of time usually
  32          * is less efficient, but it avoids bursty page faults.
  33          */
  34 -       if (!force_scan && !(arch_has_hw_pte_young() && get_cap(LRU_GEN_MM_WALK))) {
  35 +       if (!arch_has_hw_pte_young() || !get_cap(LRU_GEN_MM_WALK)) {
  36                 success = iterate_mm_list_nowalk(lruvec, max_seq);
  37                 goto done;
  38         }