[PATCH] mm/slub: drop duplicate kernel-doc for ksize()

[PATCH] mm/slub: drop duplicate kernel-doc for ksize()

[Sanjay Chitroda]

From: Sanjay Chitroda <sanjayembeddedse@gmail.com>

The ksize() API is already documented in the public header, and
Documentation/core-api/mm-api.rst pulls that canonical doc into the
book. The kernel-doc block added to mm/slub.c by commit
fab0694646d7 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
introduced a second definition for the same symbol in the generated
docs, which makes Sphinx emit:

  WARNING: Duplicate C declaration, also defined at core-api/mm-api:521
  Declaration is '.. c:function:: size_t ksize(const void *objp)'

Remove the redundant kernel-doc comment from slub.c so only the
header-provided documentation is emitted. This keeps the user-visible
API documentation intact while eliminating the duplicate-declaration
warning during `make htmldocs`.

No functional change.

Fixes: fab0694646d7 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
Signed-off-by: Sanjay Chitroda <sanjayembeddedse@gmail.com>
---
 mm/slub.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 865bc050f654..3f58a485e95e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -6309,18 +6309,6 @@ static size_t __ksize(const void *object)
 	return slab_ksize(slab);
 }
 
-/**
- * ksize -- Report full size of underlying allocation
- * @objp: pointer to the object
- *
- * This should only be used internally to query the true size of allocations.
- * It is not meant to be a way to discover the usable size of an allocation
- * after the fact. Instead, use kmalloc_size_roundup(). Using memory beyond
- * the originally requested allocation size may trigger KASAN, UBSAN_BOUNDS,
- * and/or FORTIFY_SOURCE.
- *
- * Return: size of the actual memory used by @objp in bytes
- */
 size_t ksize(const void *objp)
 {
 	/*
-- 
2.34.1

Re: [PATCH] mm/slub: drop duplicate kernel-doc for ksize()

[David Rientjes]

On Fri, 20 Feb 2026, Sanjay Chitroda wrote:

> From: Sanjay Chitroda <sanjayembeddedse@gmail.com>
> 
> The ksize() API is already documented in the public header, and
> Documentation/core-api/mm-api.rst pulls that canonical doc into the
> book. The kernel-doc block added to mm/slub.c by commit
> fab0694646d7 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
> introduced a second definition for the same symbol in the generated
> docs, which makes Sphinx emit:
> 
>   WARNING: Duplicate C declaration, also defined at core-api/mm-api:521
>   Declaration is '.. c:function:: size_t ksize(const void *objp)'
> 
> Remove the redundant kernel-doc comment from slub.c so only the
> header-provided documentation is emitted. This keeps the user-visible
> API documentation intact while eliminating the duplicate-declaration
> warning during `make htmldocs`.
> 
> No functional change.
> 
> Fixes: fab0694646d7 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
> Signed-off-by: Sanjay Chitroda <sanjayembeddedse@gmail.com>

The header file kernel-doc looks equivalent without mentioning that it 
returns bytes.  Might be best to make that clear in slab.h?

Re: [PATCH] mm/slub: drop duplicate kernel-doc for ksize()

[Sanjay Chitroda]

> The header file kernel-doc looks equivalent without mentioning that it
> returns bytes.  Might be best to make that clear in slab.h?

shall we add dedicated change in slab.h to add return bytes information?
this would keep this change as clean, what do you suggest?

Re: [PATCH] mm/slub: drop duplicate kernel-doc for ksize()

[Matthew Wilcox]

On Fri, Feb 20, 2026 at 06:12:43PM +0530, Sanjay Chitroda wrote:
> The ksize() API is already documented in the public header, and
> Documentation/core-api/mm-api.rst pulls that canonical doc into the
> book. The kernel-doc block added to mm/slub.c by commit
> fab0694646d7 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
> introduced a second definition for the same symbol in the generated
> docs, which makes Sphinx emit:
> 
>   WARNING: Duplicate C declaration, also defined at core-api/mm-api:521
>   Declaration is '.. c:function:: size_t ksize(const void *objp)'
> 
> Remove the redundant kernel-doc comment from slub.c so only the

Usually we keep the kernel-doc comment with the implementation, not with
the prototype.