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authorAndy Whitcroft <apw@shadowen.org>2007-10-16 01:24:11 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:42:51 -0700
commit540557b9439ec19668553830c90222f9fb0c2e95 (patch)
tree07dfa0e88580d4101dbb11ebc59348233e18b2f0 /include/linux/mmzone.h
parentcd881a6b22902b356cacf8fd2e4e895871068eec (diff)
downloadop-kernel-dev-540557b9439ec19668553830c90222f9fb0c2e95.zip
op-kernel-dev-540557b9439ec19668553830c90222f9fb0c2e95.tar.gz
sparsemem: record when a section has a valid mem_map
We have flags to indicate whether a section actually has a valid mem_map associated with it. This is never set and we rely solely on the present bit to indicate a section is valid. By definition a section is not valid if it has no mem_map and there is a window during init where the present bit is set but there is no mem_map, during which pfn_valid() will return true incorrectly. Use the existing SECTION_HAS_MEM_MAP flag to indicate the presence of a valid mem_map. Switch valid_section{,_nr} and pfn_valid() to this bit. Add a new present_section{,_nr} and pfn_present() interfaces for those users who care to know that a section is going to be valid. [akpm@linux-foundation.org: coding-syle fixes] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h16
1 files changed, 14 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4e56273..f21e595 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -771,12 +771,17 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section)
return (struct page *)map;
}
-static inline int valid_section(struct mem_section *section)
+static inline int present_section(struct mem_section *section)
{
return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
}
-static inline int section_has_mem_map(struct mem_section *section)
+static inline int present_section_nr(unsigned long nr)
+{
+ return present_section(__nr_to_section(nr));
+}
+
+static inline int valid_section(struct mem_section *section)
{
return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
}
@@ -798,6 +803,13 @@ static inline int pfn_valid(unsigned long pfn)
return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
}
+static inline int pfn_present(unsigned long pfn)
+{
+ if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+ return 0;
+ return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
+}
+
/*
* These are _only_ used during initialisation, therefore they
* can use __initdata ... They could have names to indicate
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