[PATCH v3 04/16] mm: eliminate is_swap_pte() when softleaf_from_pte() suffices

Lorenzo Stoakes
2025-11-10T22:23:46Z

In cases where we can simply utilise the fact that softleaf_from_pte()
treats present entries as if they were none entries and thus eliminate
spurious uses of is_swap_pte(), do so.

No functional change intended.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
mm/internal.h | 7 +++----
mm/madvise.c | 8 +++-----
mm/swap_state.c | 12 ++++++------
mm/swapfile.c | 9 ++++-----
4 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 9465129367a4..f0c7461bb02c 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -15,7 +15,7 @@
#include <linux/pagewalk.h>
#include <linux/rmap.h>
#include <linux/swap.h>
-#include <linux/swapops.h>
+#include <linux/leafops.h>
#include <linux/swap_cgroup.h>
#include <linux/tracepoint-defs.h>

@@ -380,13 +380,12 @@ static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
{
pte_t expected_pte = pte_next_swp_offset(pte);
const pte_t *end_ptep = start_ptep + max_nr;
- swp_entry_t entry = pte_to_swp_entry(pte);
+ const softleaf_t entry = softleaf_from_pte(pte);
pte_t *ptep = start_ptep + 1;
unsigned short cgroup_id;

VM_WARN_ON(max_nr < 1);
- VM_WARN_ON(!is_swap_pte(pte));
- VM_WARN_ON(non_swap_entry(entry));
+ VM_WARN_ON(!softleaf_is_swap(entry));

cgroup_id = lookup_swap_cgroup_id(entry);
while (ptep < end_ptep) {
diff --git a/mm/madvise.c b/mm/madvise.c
index 2d5ad3cb37bb..58d82495b6c6 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -195,7 +195,7 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,

for (addr = start; addr < end; addr += PAGE_SIZE) {
pte_t pte;
- swp_entry_t entry;
+ softleaf_t entry;
struct folio *folio;

if (!ptep++) {
@@ -205,10 +205,8 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
}

pte = ptep_get(ptep);
- if (!is_swap_pte(pte))
- continue;
- entry = pte_to_swp_entry(pte);
- if (unlikely(non_swap_entry(entry)))
+ entry = softleaf_from_pte(pte);
+ if (unlikely(!softleaf_is_swap(entry)))
continue;

pte_unmap_unlock(ptep, ptl);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index d20d238109f9..8881a79f200c 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -12,7 +12,7 @@
#include <linux/kernel_stat.h>
#include <linux/mempolicy.h>
#include <linux/swap.h>
-#include <linux/swapops.h>
+#include <linux/leafops.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
@@ -732,7 +732,6 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
pte_t *pte = NULL, pentry;
int win;
unsigned long start, end, addr;
- swp_entry_t entry;
pgoff_t ilx;
bool page_allocated;

@@ -744,16 +743,17 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,

blk_start_plug(&plug);
for (addr = start; addr < end; ilx++, addr += PAGE_SIZE) {
+ softleaf_t entry;
+
if (!pte++) {
pte = pte_offset_map(vmf->pmd, addr);
if (!pte)
break;
}
pentry = ptep_get_lockless(pte);
- if (!is_swap_pte(pentry))
- continue;
- entry = pte_to_swp_entry(pentry);
- if (unlikely(non_swap_entry(entry)))
+ entry = softleaf_from_pte(pentry);
+
+ if (!softleaf_is_swap(entry))
continue;
pte_unmap(pte);
pte = NULL;
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 543f303f101d..684f78cd7dd1 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -44,7 +44,7 @@
#include <linux/plist.h>

#include <asm/tlbflush.h>
-#include <linux/swapops.h>
+#include <linux/leafops.h>
#include <linux/swap_cgroup.h>
#include "swap_table.h"
#include "internal.h"
@@ -2256,7 +2256,7 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
struct folio *folio;
unsigned long offset;
unsigned char swp_count;
- swp_entry_t entry;
+ softleaf_t entry;
int ret;
pte_t ptent;

@@ -2267,11 +2267,10 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
}

ptent = ptep_get_lockless(pte);
+ entry = softleaf_from_pte(ptent);

- if (!is_swap_pte(ptent))
+ if (!softleaf_is_swap(entry))
continue;
-
- entry = pte_to_swp_entry(ptent);
if (swp_type(entry) != type)
continue;

--
2.51.0