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| author | Dave Hansen <haveblue@us.ibm.com> | 2005-09-04 00:54:29 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 09:05:38 +0200 |
| commit | 28ae55c98e4d16eac9a05a8a259d7763ef3aeb18 (patch) | |
| tree | 0ac0a08d88a692b9b9934344b5e439058d71772a /mm/sparse.c | |
| parent | [PATCH] sparsemem extreme implementation (diff) | |
| download | linux-28ae55c98e4d16eac9a05a8a259d7763ef3aeb18.tar.xz linux-28ae55c98e4d16eac9a05a8a259d7763ef3aeb18.zip | |
[PATCH] sparsemem extreme: hotplug preparation
This splits up sparse_index_alloc() into two pieces. This is needed
because we'll allocate the memory for the second level in a different place
from where we actually consume it to keep the allocation from happening
underneath a lock
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Bob Picco <bob.picco@hp.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/sparse.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/mm/sparse.c b/mm/sparse.c index fa01292157a9..347249a4917a 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -6,6 +6,7 @@ #include <linux/mmzone.h> #include <linux/bootmem.h> #include <linux/module.h> +#include <linux/spinlock.h> #include <asm/dma.h> /* @@ -22,27 +23,55 @@ struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] #endif EXPORT_SYMBOL(mem_section); -static void sparse_alloc_root(unsigned long root, int nid) -{ #ifdef CONFIG_SPARSEMEM_EXTREME - mem_section[root] = alloc_bootmem_node(NODE_DATA(nid), PAGE_SIZE); -#endif +static struct mem_section *sparse_index_alloc(int nid) +{ + struct mem_section *section = NULL; + unsigned long array_size = SECTIONS_PER_ROOT * + sizeof(struct mem_section); + + section = alloc_bootmem_node(NODE_DATA(nid), array_size); + + if (section) + memset(section, 0, array_size); + + return section; } -static void sparse_index_init(unsigned long section, int nid) +static int sparse_index_init(unsigned long section_nr, int nid) { - unsigned long root = SECTION_NR_TO_ROOT(section); + static spinlock_t index_init_lock = SPIN_LOCK_UNLOCKED; + unsigned long root = SECTION_NR_TO_ROOT(section_nr); + struct mem_section *section; + int ret = 0; if (mem_section[root]) - return; + return -EEXIST; - sparse_alloc_root(root, nid); + section = sparse_index_alloc(nid); + /* + * This lock keeps two different sections from + * reallocating for the same index + */ + spin_lock(&index_init_lock); - if (mem_section[root]) - memset(mem_section[root], 0, PAGE_SIZE); - else - panic("memory_present: NO MEMORY\n"); + if (mem_section[root]) { + ret = -EEXIST; + goto out; + } + + mem_section[root] = section; +out: + spin_unlock(&index_init_lock); + return ret; } +#else /* !SPARSEMEM_EXTREME */ +static inline int sparse_index_init(unsigned long section_nr, int nid) +{ + return 0; +} +#endif + /* Record a memory area against a node. */ void memory_present(int nid, unsigned long start, unsigned long end) { |