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mm, sparse: Put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE

PATCH In review Zhang Yanfei 2 participants 2 messages Jun 18, 2013

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Zhang Yanfei

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PATCH 1/1 mm, sparse: Put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE

From: Zhang Yanfei <[email protected]>

With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:

mm/sparse.c:755: warning: a??clear_hwpoisoned_pagesa?? defined but not used

And Bisecting it ended up pointing to:

commit 4edd7ceff0662afde195da6f6c43e7cbe1ed2dc4

Author: David Rientjes <[email protected]>
Date:   Mon Apr 29 15:08:22 2013 -0700

mm, hotplug: avoid compiling memory hotremove functions when disabled

__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE. PowerPC pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also become unnecessary, which saves in .text when disabled (it's disabled in most defconfigs besides powerpc, including x86). remove_memory_block() becomes static since it is not referenced outside of drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled and disabled.

Signed-off-by David Rientjes <[email protected]>
Acked-by Toshi Kani <[email protected]>
Cc Benjamin Herrenschmidt <[email protected]>
Cc Paul Mackerras <[email protected]>
Cc Greg Kroah-Hartman <[email protected]>
Cc Wen Congyang <[email protected]>
Cc Tang Chen <[email protected]>
Cc Yasuaki Ishimatsu <[email protected]>
Signed-off-by Andrew Morton <[email protected]>
Signed-off-by Linus Torvalds <[email protected]>

This is because the commit above put function sparse_remove_one_section within the protection of CONFIG_MEMORY_HOTREMOVE but the only user of function clear_hwpoisoned_pages is sparse_remove_one_section, and it is not within the protection of CONFIG_MEMORY_HOTREMOVE.

So put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE should fix the warning.

Signed-off-by Zhang Yanfei <[email protected]>
Cc David Rientjes <[email protected]>
Cc Toshi Kani <[email protected]>
---
 mm/sparse.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
mm/sparse.c +1 -1
index 1c91f0d..999a1fe 100644
@@ -751,6 +751,7 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
 #ifdef CONFIG_MEMORY_FAILURE
 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 {

@@ -772,7 +773,6 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 }
 #endif
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 {
 	struct page *usemap_page;
Signature · 7 lines
1.7.1

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Acked-by on v1 1/1
#1 lore raw
Quoted 42 lines · Zhang Yanfei

From: Zhang Yanfei <[email protected]>

With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:

mm/sparse.c:755: warning: a??clear_hwpoisoned_pagesa?? defined but not used

And Bisecting it ended up pointing to:

commit 4edd7ceff0662afde195da6f6c43e7cbe1ed2dc4

Author: David Rientjes <[email protected]>
Date:   Mon Apr 29 15:08:22 2013 -0700

mm, hotplug: avoid compiling memory hotremove functions when disabled

__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE. PowerPC pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also become unnecessary, which saves in .text when disabled (it's disabled in most defconfigs besides powerpc, including x86). remove_memory_block() becomes static since it is not referenced outside of drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled and disabled.

Signed-off-by David Rientjes <[email protected]>
Acked-by Toshi Kani <[email protected]>
Cc Benjamin Herrenschmidt <[email protected]>
Cc Paul Mackerras <[email protected]>
Cc Greg Kroah-Hartman <[email protected]>
Cc Wen Congyang <[email protected]>
Cc Tang Chen <[email protected]>
Cc Yasuaki Ishimatsu <[email protected]>
Signed-off-by Andrew Morton <[email protected]>
Signed-off-by Linus Torvalds <[email protected]>

This is because the commit above put function sparse_remove_one_section within the protection of CONFIG_MEMORY_HOTREMOVE but the only user of function clear_hwpoisoned_pages is sparse_remove_one_section, and it is not within the protection of CONFIG_MEMORY_HOTREMOVE.

Quoted 6 lines

So put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE should fix the warning.

Signed-off-by Zhang Yanfei <[email protected]>
Cc David Rientjes <[email protected]>
Cc Toshi Kani <[email protected]>

Looks good.

Acked-by Toshi Kani <[email protected]>

Thanks,
-Toshi

Quoted 16 lines
 mm/sparse.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
mm/sparse.c +1 -0
index 1c91f0d..999a1fe 100644
@@ -751,6 +751,7 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
 #ifdef CONFIG_MEMORY_FAILURE
 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 {

mm/sparse.c static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) · line 778

Quoted 7 lines
mm/sparse.c +0 -1
@@ -772,7 +773,6 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 }
 #endif
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 {
 	struct page *usemap_page;

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