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| author | Andy Whitcroft | 2007-10-16 10:24:11 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2007-10-16 18:42:51 +0200 |
| commit | 540557b9439ec19668553830c90222f9fb0c2e95 (patch) | |
| tree | 07dfa0e88580d4101dbb11ebc59348233e18b2f0 /include/linux/mmzone.h | |
| parent | sparsemem: clean up spelling error in comments (diff) | |
| download | kernel-qcow2-linux-540557b9439ec19668553830c90222f9fb0c2e95.tar.gz kernel-qcow2-linux-540557b9439ec19668553830c90222f9fb0c2e95.tar.xz kernel-qcow2-linux-540557b9439ec19668553830c90222f9fb0c2e95.zip | |
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.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4e5627379b09..f21e5951038b 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 |