The patch titled
sparsemem: record when a section has a valid mem_map
has been added to the -mm tree. Its filename is
sparsemem-record-when-a-section-has-a-valid-mem_map.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: sparsemem: record when a section has a valid mem_map
From: Andy Whitcroft <apw@xxxxxxxxxxxx>
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.
Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxx>
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxx>
Cc: "Luck, Tony" <tony.luck@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/memory.c | 6 +++---
include/linux/mmzone.h | 16 ++++++++++++++--
mm/sparse.c | 9 +++++----
3 files changed, 22 insertions(+), 9 deletions(-)
diff -puN drivers/base/memory.c~sparsemem-record-when-a-section-has-a-valid-mem_map drivers/base/memory.c
--- a/drivers/base/memory.c~sparsemem-record-when-a-section-has-a-valid-mem_map
+++ a/drivers/base/memory.c
@@ -239,7 +239,7 @@ store_mem_state(struct sys_device *dev,
mem = container_of(dev, struct memory_block, sysdev);
phys_section_nr = mem->phys_index;
- if (!valid_section_nr(phys_section_nr))
+ if (!present_section_nr(phys_section_nr))
goto out;
if (!strncmp(buf, "online", min((int)count, 6)))
@@ -419,7 +419,7 @@ int register_new_memory(struct mem_secti
int unregister_memory_section(struct mem_section *section)
{
- if (!valid_section(section))
+ if (!present_section(section))
return -EINVAL;
return remove_memory_block(0, section, 0);
@@ -444,7 +444,7 @@ int __init memory_dev_init(void)
* during boot and have been initialized
*/
for (i = 0; i < NR_MEM_SECTIONS; i++) {
- if (!valid_section_nr(i))
+ if (!present_section_nr(i))
continue;
err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
if (!ret)
diff -puN include/linux/mmzone.h~sparsemem-record-when-a-section-has-a-valid-mem_map include/linux/mmzone.h
--- a/include/linux/mmzone.h~sparsemem-record-when-a-section-has-a-valid-mem_map
+++ a/include/linux/mmzone.h
@@ -754,12 +754,17 @@ static inline struct page *__section_mem
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));
}
@@ -781,6 +786,13 @@ static inline int pfn_valid(unsigned lon
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
diff -puN mm/sparse.c~sparsemem-record-when-a-section-has-a-valid-mem_map mm/sparse.c
--- a/mm/sparse.c~sparsemem-record-when-a-section-has-a-valid-mem_map
+++ a/mm/sparse.c
@@ -170,7 +170,7 @@ unsigned long __init node_memmap_size_by
if (nid != early_pfn_to_nid(pfn))
continue;
- if (pfn_valid(pfn))
+ if (pfn_present(pfn))
nr_pages += PAGES_PER_SECTION;
}
@@ -200,11 +200,12 @@ struct page *sparse_decode_mem_map(unsig
static int __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map)
{
- if (!valid_section(ms))
+ if (!present_section(ms))
return -EINVAL;
ms->section_mem_map &= ~SECTION_MAP_MASK;
- ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum);
+ ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
+ SECTION_HAS_MEM_MAP;
return 1;
}
@@ -250,7 +251,7 @@ void __init sparse_init(void)
struct page *map;
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
- if (!valid_section_nr(pnum))
+ if (!present_section_nr(pnum))
continue;
map = sparse_early_mem_map_alloc(pnum);
_
Patches currently in -mm which might be from apw@xxxxxxxxxxxx are
origin.patch
sparsemem-clean-up-spelling-error-in-comments.patch
sparsemem-record-when-a-section-has-a-valid-mem_map.patch
sparsemem-record-when-a-section-has-a-valid-mem_map-fix.patch
generic-virtual-memmap-support-for-sparsemem.patch
x86_64-sparsemem_vmemmap-2m-page-size-support.patch
ia64-sparsemem_vmemmap-16k-page-size-support.patch
sparc64-sparsemem_vmemmap-support.patch
ppc64-sparsemem_vmemmap-support.patch
add-a-bitmap-that-is-used-to-track-flags-affecting-a-block-of-pages.patch
add-a-configure-option-to-group-pages-by-mobility.patch
move-free-pages-between-lists-on-steal.patch
group-short-lived-and-reclaimable-kernel-allocations.patch
do-not-group-pages-by-mobility-type-on-low-memory-systems.patch
fix-corruption-of-memmap-on-ia64-sparsemem-when-mem_section-is-not-a-power-of-2.patch
bias-the-location-of-pages-freed-for-min_free_kbytes-in-the-same-max_order_nr_pages-blocks.patch
remove-page_group_by_mobility.patch
dont-group-high-order-atomic-allocations.patch
fix-calculation-in-move_freepages_block-for-counting-pages.patch
breakout-page_order-to-internalh-to-avoid-special-knowledge-of-the-buddy-allocator.patch
do-not-depend-on-max_order-when-grouping-pages-by-mobility.patch
print-out-statistics-in-relation-to-fragmentation-avoidance-to-proc-pagetypeinfo.patch
have-kswapd-keep-a-minimum-order-free-other-than-order-0.patch
only-check-absolute-watermarks-for-alloc_high-and-alloc_harder-allocations.patch
rename-gfp_high_movable-to-gfp_highuser_movable-prefetch.patch
page-owner-tracking-leak-detector.patch
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