mm/zsmalloc: fix -Wunneeded-internal-declaration warning

PATCH Applied Nick Desaulniers 3 participants 4 messages May 24, 2017 – May 26, 2017

Subsystems (2)

Memory management Zsmalloc compressed slab memory allocator

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Nick Desaulniers

author

2017-05-24 05:42 UTC #0 lore raw

PATCH 1/1 mm/zsmalloc: fix -Wunneeded-internal-declaration warning

is_first_page() is only called from the macro VM_BUG_ON_PAGE() which is only compiled in as a runtime check when CONFIG_DEBUG_VM is set, otherwise is checked at compile time and not actually compiled in.

Fixes the following warning, found with Clang:

mm/zsmalloc.c:472:12: warning: function 'is_first_page' is not needed and will not be emitted [-Wunneeded-internal-declaration]
static int is_first_page(struct page *page)

Signed-off-by Nick Desaulniers <[email protected]>

---
 mm/zsmalloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

mm/zsmalloc.c +1 -1

index d41edd28298b..15959d35fc26 100644
@@ -469,7 +469,7 @@ static bool is_zspage_isolated(struct zspage *zspage)
 	return zspage->isolated;
 }
 
-static int is_first_page(struct page *page)
+static __maybe_unused int is_first_page(struct page *page)
 {
 	return PagePrivate(page);
 }

Signature · 7 lines

2.11.0

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Sergey Senozhatsky

Reviewed-by on v1 1/1

2017-05-24 08:16 UTC #1 lore raw

Quoted 5 lines · Nick Desaulniers

is_first_page() is only called from the macro VM_BUG_ON_PAGE() which is only compiled in as a runtime check when CONFIG_DEBUG_VM is set, otherwise is checked at compile time and not actually compiled in.

Quoted 8 lines

Fixes the following warning, found with Clang:
mm/zsmalloc.c:472:12: warning: function 'is_first_page' is not needed and will not be emitted [-Wunneeded-internal-declaration]
static int is_first_page(struct page *page)
           ^
Signed-off-by Nick Desaulniers <[email protected]>

well, no objections from my side. MM seems to be getting more and more `__maybe_unused' annotations because of clang.

Reviewed-by Sergey Senozhatsky <[email protected]>

-ss

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Nick Desaulniers

author

2017-05-26 04:15 UTC #2 lore raw

Quoted 4 lines · Sergey Senozhatsky

Quoted 1 line · Nick Desaulniers
Fixes the following warning, found with Clang:
well, no objections from my side. MM seems to be getting more and more `__maybe_unused' annotations because of clang.

Indeed, but does find bugs when this warning pops up unexpected (unlike in this particular instance). See:

https://patchwork.kernel.org/patch/9738897/
https://www.spinics.net/lists/intel-gfx/msg128737.html

TL;DR

Quoted 2 lines

Quoted 2 lines
Quoted 2 lines
You have actually uncovered a bug here where the call is not supposed to be optional in the first place.

Minchan Kim

maintainer Acked-by on v1 1/1

2017-05-25 05:38 UTC #3 lore raw

In reply to Nick Desaulniers

Quoted 4 lines · Nick Desaulniers

is_first_page() is only called from the macro VM_BUG_ON_PAGE() which is only compiled in as a runtime check when CONFIG_DEBUG_VM is set, otherwise is checked at compile time and not actually compiled in.

Quoted 8 lines

Fixes the following warning, found with Clang:
mm/zsmalloc.c:472:12: warning: function 'is_first_page' is not needed and will not be emitted [-Wunneeded-internal-declaration]
static int is_first_page(struct page *page)
           ^
Signed-off-by Nick Desaulniers <[email protected]>

Acked-by Minchan Kim <[email protected]>

Thanks.