[PATCH v1 1/1] mm/page_alloc: Mark has_unaccepted_memory() with __maybe_unused

[PATCH v1 1/1] mm/page_alloc: Mark has_unaccepted_memory() with __maybe_unused

[Andy Shevchenko]

When has_unaccepted_memory() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:

mm/page_alloc.c:7036:20: error: unused function 'has_unaccepted_memory' [-Werror,-Wunused-function]
 7036 | static inline bool has_unaccepted_memory(void)
      |                    ^~~~~~~~~~~~~~~~~~~~~

Fix this by marking it with __maybe_unused (all cases for the sake of
symmetry).

See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 mm/page_alloc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c565de8f48e9..3b47f1b17ae5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6990,7 +6990,7 @@ static bool cond_accept_memory(struct zone *zone, unsigned int order)
 	return ret;
 }
 
-static inline bool has_unaccepted_memory(void)
+static inline __maybe_unused bool has_unaccepted_memory(void)
 {
 	return static_branch_unlikely(&zones_with_unaccepted_pages);
 }
@@ -7033,7 +7033,7 @@ static bool cond_accept_memory(struct zone *zone, unsigned int order)
 	return false;
 }
 
-static inline bool has_unaccepted_memory(void)
+static inline __maybe_unused bool has_unaccepted_memory(void)
 {
 	return false;
 }
-- 
2.43.0.rc1.1336.g36b5255a03ac

Re: [PATCH v1 1/1] mm/page_alloc: Mark has_unaccepted_memory() with __maybe_unused

[Andrew Morton]

On Thu,  5 Sep 2024 20:15:53 +0300 Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> When has_unaccepted_memory() is unused, it prevents kernel builds
> with clang, `make W=1` and CONFIG_WERROR=y:
> 
> mm/page_alloc.c:7036:20: error: unused function 'has_unaccepted_memory' [-Werror,-Wunused-function]
>  7036 | static inline bool has_unaccepted_memory(void)
>       |                    ^~~~~~~~~~~~~~~~~~~~~
> 
> Fix this by marking it with __maybe_unused (all cases for the sake of
> symmetry).
> 
> See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
> inline functions for W=1 build").
> 

has_unaccepted_memory() has no callers if CONFIG_UNACCEPTED_MEMORY=n. 
Can't we do this better thing?


--- a/mm/page_alloc.c~a
+++ a/mm/page_alloc.c
@@ -288,7 +288,6 @@ EXPORT_SYMBOL(nr_online_nodes);
 static bool page_contains_unaccepted(struct page *page, unsigned int order);
 static void accept_page(struct page *page, unsigned int order);
 static bool cond_accept_memory(struct zone *zone, unsigned int order);
-static inline bool has_unaccepted_memory(void);
 static bool __free_unaccepted(struct page *page);
 
 int page_group_by_mobility_disabled __read_mostly;
@@ -6963,6 +6962,11 @@ static bool try_to_accept_memory_one(str
 	return true;
 }
 
+static inline bool has_unaccepted_memory(void)
+{
+	return static_branch_unlikely(&zones_with_unaccepted_pages);
+}
+
 static bool cond_accept_memory(struct zone *zone, unsigned int order)
 {
 	long to_accept;
@@ -6990,11 +6994,6 @@ static bool cond_accept_memory(struct zo
 	return ret;
 }
 
-static inline bool has_unaccepted_memory(void)
-{
-	return static_branch_unlikely(&zones_with_unaccepted_pages);
-}
-
 static bool __free_unaccepted(struct page *page)
 {
 	struct zone *zone = page_zone(page);
@@ -7032,11 +7031,6 @@ static bool cond_accept_memory(struct zo
 {
 	return false;
 }
-
-static inline bool has_unaccepted_memory(void)
-{
-	return false;
-}
 
 static bool __free_unaccepted(struct page *page)
 {
_

Re: [PATCH v1 1/1] mm/page_alloc: Mark has_unaccepted_memory() with __maybe_unused

[Andy Shevchenko]

Thu, Sep 05, 2024 at 02:22:20PM -0700, Andrew Morton kirjoitti:
> On Thu,  5 Sep 2024 20:15:53 +0300 Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> 
> > When has_unaccepted_memory() is unused, it prevents kernel builds
> > with clang, `make W=1` and CONFIG_WERROR=y:
> > 
> > mm/page_alloc.c:7036:20: error: unused function 'has_unaccepted_memory' [-Werror,-Wunused-function]
> >  7036 | static inline bool has_unaccepted_memory(void)
> >       |                    ^~~~~~~~~~~~~~~~~~~~~
> > 
> > Fix this by marking it with __maybe_unused (all cases for the sake of
> > symmetry).
> > 
> > See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
> > inline functions for W=1 build").
> 
> has_unaccepted_memory() has no callers if CONFIG_UNACCEPTED_MEMORY=n. 
> Can't we do this better thing?

Sure! Please, use your patch, I'm fine with that
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko