[PATCH v3 0/3] mm: Coccinelle-driven cleanups across memory management code

[PATCH v3 0/3] mm: Coccinelle-driven cleanups across memory management code

[Sahil Chandna]

This patch series contains three minor cleanups identified by
Coccinelle scripts under scripts/coccinelle/misc/:

  * Replace manual ternary expression with the min() macro in pagewalk.c
    and change return expression for clarity.
  * Use the %pe printk format specifier for PTR_ERR() reporting
    in vmscan.c and zswap.c
Found using:
  make coccicheck MODE=report M=mm/

changes since v1 and v2:
- Patch 1/3: update return value as per review comments.
- patch 2/3 and 3/3: Add Acked-by and Reviewed-by tags.

link to v1: https://lore.kernel.org/all/cover.1763227530.git.chandna.sahil@gmail.com/
link to v2: https://lore.kernel.org/all/cover.1763796152.git.chandna.sahil@gmail.com/

Sahil Chandna (3):
  mm: pagewalk: simplify hugepage boundary calculation using min()
  mm/vmscan: use %pe to print error pointers
  mm/zswap: use %pe to print error pointers

 mm/pagewalk.c | 3 +--
 mm/vmscan.c   | 4 ++--
 mm/zswap.c    | 4 ++--
 3 files changed, 5 insertions(+), 6 deletions(-)

-- 
2.50.1

[PATCH v3 1/3] mm: pagewalk: simplify hugepage boundary calculation using min()

[Sahil Chandna]

Use the min() macro to compute the minimum value instead of an explicit 
ternary expression. This improves readability and matches common kernel 
style. Also change the return hugepage boundary expression for better
clarity.

This was flagged by Coccinelle
(misc/minmax.cocci) as an opportunity to use min().

Found by: make coccicheck MODE=report M=mm/
No functional change intended.

Suggested-by: David Hildenbrand (Red Hat) <david@kernel.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
---
changes since v2:
- change the return expression for readability and clarity. 
changes since v1:
- Updated boundary calculation of huge page range for better clarity.
- No Functional changes intended.
link to v1: https://lore.kernel.org/all/ff24b3c573b766b187b55a38497fbad0a319b9f8.1763227530.git.chandna.sahil@gmail.com/
link to v2: https://lore.kernel.org/all/f802959f58865371ba1b10081bced98e3784c5e4.1763796152.git.chandna.sahil@gmail.com/
---
 mm/pagewalk.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 9f91cf85a5be..9fd59d517f37 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -312,8 +312,7 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
 static unsigned long hugetlb_entry_end(struct hstate *h, unsigned long addr,
 				       unsigned long end)
 {
-	unsigned long boundary = (addr & huge_page_mask(h)) + huge_page_size(h);
-	return boundary < end ? boundary : end;
+	return min(ALIGN(addr, huge_page_size(h)), end);
 }
 
 static int walk_hugetlb_range(unsigned long addr, unsigned long end,
-- 
2.50.1

[PATCH v3 2/3] mm/vmscan: use %pe to print error pointers

[Sahil Chandna]

Use the %pe printk format specifier to report error pointers directly
instead of printing PTR_ERR() as a long value. This improves clarity,
produces more readable error messages.

This instance was flagged by the Coccinelle script
(misc/ptr_err_to_pe.cocci) as an opportunity to adopt %pe.

Found by: make coccicheck MODE=report M=mm/
No functional change intended

Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
---
changes since v2:
- Add Acked-by tag
link to v2: https://lore.kernel.org/all/64e15c6b2ce86d7824f54e9e001b6f5b44af48b8.1763796152.git.chandna.sahil@gmail.com/
---
 mm/vmscan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index b2fc8b626d3d..29ed0b304b5c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -7500,8 +7500,8 @@ void __meminit kswapd_run(int nid)
 		pgdat->kswapd = kthread_create_on_node(kswapd, pgdat, nid, "kswapd%d", nid);
 		if (IS_ERR(pgdat->kswapd)) {
 			/* failure at boot is fatal */
-			pr_err("Failed to start kswapd on node %d,ret=%ld\n",
-				   nid, PTR_ERR(pgdat->kswapd));
+			pr_err("Failed to start kswapd on node %d, ret=%pe\n",
+				   nid, pgdat->kswapd);
 			BUG_ON(system_state < SYSTEM_RUNNING);
 			pgdat->kswapd = NULL;
 		} else {
-- 
2.50.1

[PATCH v3 3/3] mm/zswap: use %pe to print error pointers

[Sahil Chandna]

Use the %pe printk format specifier to report error pointers directly
instead of printing PTR_ERR() as a long value. This improves clarity,
produces more readable error messages.

This instance was flagged by the Coccinelle script
(misc/ptr_err_to_pe.cocci) as an opportunity to adopt %pe.

Found by: make coccicheck MODE=report M=mm/
No functional change intended.

Acked-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
---
Changes since v2:
- Add Acked-by tag.
link to v2: https://lore.kernel.org/all/0c00ceedce6e0d9aed35cee5faf15fd9126a1f70.1763796152.git.chandna.sahil@gmail.com/
---
 mm/zswap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index c1af782e54ec..c35604db32ad 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -749,8 +749,8 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
 
 	acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu));
 	if (IS_ERR(acomp)) {
-		pr_err("could not alloc crypto acomp %s : %ld\n",
-				pool->tfm_name, PTR_ERR(acomp));
+		pr_err("could not alloc crypto acomp %s : %pe\n",
+				pool->tfm_name, acomp);
 		ret = PTR_ERR(acomp);
 		goto fail;
 	}
-- 
2.50.1

Re: [PATCH v3 1/3] mm: pagewalk: simplify hugepage boundary calculation using min()

[David Hildenbrand (Red Hat)]

On 11/27/25 06:11, Sahil Chandna wrote:
> Use the min() macro to compute the minimum value instead of an explicit
> ternary expression. This improves readability and matches common kernel
> style. Also change the return hugepage boundary expression for better
> clarity.
> 
> This was flagged by Coccinelle
> (misc/minmax.cocci) as an opportunity to use min().
> 
> Found by: make coccicheck MODE=report M=mm/
> No functional change intended.
> 
> Suggested-by: David Hildenbrand (Red Hat) <david@kernel.org>
> Suggested-by: Matthew Wilcox <willy@infradead.org>
> Suggested-by: David Laight <david.laight.linux@gmail.com>
> Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
> ---

Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>

-- 
Cheers

David

Re: [PATCH v3 1/3] mm: pagewalk: simplify hugepage boundary calculation using min()

[David Laight]

On Thu, 27 Nov 2025 10:41:28 +0530
Sahil Chandna <chandna.sahil@gmail.com> wrote:

> Use the min() macro to compute the minimum value instead of an explicit 
> ternary expression. This improves readability and matches common kernel 
> style. Also change the return hugepage boundary expression for better
> clarity.
> 
>...
>  {
> -	unsigned long boundary = (addr & huge_page_mask(h)) + huge_page_size(h);
> -	return boundary < end ? boundary : end;
> +	return min(ALIGN(addr, huge_page_size(h)), end);
>  }
>  
>  static int walk_hugetlb_range(unsigned long addr, unsigned long end,

The commit message doesn't really match the patch.
The biggest part is not open-coding the equivalent of ALIGN(), not using min().

	David