The patch titled
Subject: mm: swap_pte_batch: add an output argument to reture if all swap entries are exclusive
has been added to the -mm mm-unstable branch. Its filename is
mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Barry Song <v-songbaohua@xxxxxxxx>
Subject: mm: swap_pte_batch: add an output argument to reture if all swap entries are exclusive
Date: Tue, 9 Apr 2024 20:26:29 +1200
Add a boolean argument named any_shared. If any of the swap entries are
non-exclusive, set any_shared to true. The function do_swap_page() can
then utilize this information to determine whether the entire large folio
can be reused.
Link: https://lkml.kernel.org/r/20240409082631.187483-4-21cnbao@xxxxxxxxx
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: Chuanhua Han <hanchuanhua@xxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gao Xiang <xiang@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kairui Song <kasong@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/internal.h | 9 ++++++++-
mm/madvise.c | 2 +-
mm/memory.c | 2 +-
3 files changed, 10 insertions(+), 3 deletions(-)
--- a/mm/internal.h~mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive
+++ a/mm/internal.h
@@ -241,7 +241,8 @@ static inline pte_t pte_next_swp_offset(
*
* Return: the number of table entries in the batch.
*/
-static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
+static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte,
+ bool *any_shared)
{
pte_t expected_pte = pte_next_swp_offset(pte);
const pte_t *end_ptep = start_ptep + max_nr;
@@ -251,12 +252,18 @@ static inline int swap_pte_batch(pte_t *
VM_WARN_ON(!is_swap_pte(pte));
VM_WARN_ON(non_swap_entry(pte_to_swp_entry(pte)));
+ if (any_shared)
+ *any_shared |= !pte_swp_exclusive(pte);
+
while (ptep < end_ptep) {
pte = ptep_get(ptep);
if (!pte_same(pte, expected_pte))
break;
+ if (any_shared)
+ *any_shared |= !pte_swp_exclusive(pte);
+
expected_pte = pte_next_swp_offset(expected_pte);
ptep++;
}
--- a/mm/madvise.c~mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive
+++ a/mm/madvise.c
@@ -671,7 +671,7 @@ static int madvise_free_pte_range(pmd_t
entry = pte_to_swp_entry(ptent);
if (!non_swap_entry(entry)) {
max_nr = (end - addr) / PAGE_SIZE;
- nr = swap_pte_batch(pte, max_nr, ptent);
+ nr = swap_pte_batch(pte, max_nr, ptent, NULL);
nr_swap -= nr;
free_swap_and_cache_nr(entry, nr);
clear_not_present_full_ptes(mm, addr, pte, nr, tlb->fullmm);
--- a/mm/memory.c~mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive
+++ a/mm/memory.c
@@ -1637,7 +1637,7 @@ static unsigned long zap_pte_range(struc
folio_put(folio);
} else if (!non_swap_entry(entry)) {
max_nr = (end - addr) / PAGE_SIZE;
- nr = swap_pte_batch(pte, max_nr, ptent);
+ nr = swap_pte_batch(pte, max_nr, ptent, NULL);
/* Genuine swap entries, hence a private anon pages */
if (!should_zap_cows(details))
continue;
_
Patches currently in -mm which might be from v-songbaohua@xxxxxxxx are
arm64-mm-swap-support-thp_swap-on-hardware-with-mte.patch
mm-hold-ptl-from-the-first-pte-while-reclaiming-a-large-folio.patch
mm-alloc_anon_folio-avoid-doing-vma_thp_gfp_mask-in-fallback-cases.patch
mm-add-per-order-mthp-anon_alloc-and-anon_alloc_fallback-counters.patch
mm-add-per-order-mthp-anon_alloc-and-anon_alloc_fallback-counters-fix.patch
mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch
mm-swap_pte_batch-add-an-output-argument-to-reture-if-all-swap-entries-are-exclusive.patch
mm-add-per-order-mthp-swpin_refault-counter.patch
