[PATCH] mm, sparse: Put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE

From: Zhang Yanfei
Date: Tue Jun 18 2013 - 10:31:59 EST


From: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>

With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:

mm/sparse.c:755: warning: âclear_hwpoisoned_pagesâ defined but not used

And Bisecting it ended up pointing to:

commit 4edd7ceff0662afde195da6f6c43e7cbe1ed2dc4
Author: David Rientjes <rientjes@xxxxxxxxxx>
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 <rientjes@xxxxxxxxxx>
Acked-by: Toshi Kani <toshi.kani@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Wen Congyang <wency@xxxxxxxxxxxxxx>
Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>

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 <zhangyanfei@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxx>
---
mm/sparse.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 1c91f0d..999a1fe 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -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;
--
1.7.1
--
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