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

Lorenzo Stoakes posted 16 patches 1 month, 1 week ago
[PATCH v3 04/16] mm: eliminate is_swap_pte() when softleaf_from_pte() suffices
Posted by Lorenzo Stoakes 1 month, 1 week ago
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
Re: [PATCH v3 04/16] mm: eliminate is_swap_pte() when softleaf_from_pte() suffices
Posted by Vlastimil Babka 4 weeks ago
On 11/10/25 23:21, Lorenzo Stoakes wrote:
> 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>

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>