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authorYinghai Lu <yinghai@kernel.org>2012-07-11 14:02:53 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-02 10:30:36 -0700
commit391c314928c37b0c946061c0adddd5bd5730c8b7 (patch)
tree637faa9238abb81698e4b2170bbbd9ca1d704aa7 /mm
parente194fab8d7ebe95db5609f1cb6794c2afcc3118f (diff)
mm: sparse: fix usemap allocation above node descriptor section
commit 99ab7b19440a72ebdf225f99b20f8ef40decee86 upstream. After commit f5bf18fa22f8 ("bootmem/sparsemem: remove limit constraint in alloc_bootmem_section"), usemap allocations may easily be placed outside the optimal section that holds the node descriptor, even if there is space available in that section. This results in unnecessary hotplug dependencies that need to have the node unplugged before the section holding the usemap. The reason is that the bootmem allocator doesn't guarantee a linear search starting from the passed allocation goal but may start out at a much higher address absent an upper limit. Fix this by trying the allocation with the limit at the section end, then retry without if that fails. This keeps the fix from f5bf18fa22f8 of not panicking if the allocation does not fit in the section, but still makes sure to try to stay within the section at first. [rewritten massively by Johannes to apply to 3.4] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/bootmem.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 0131170c9d54..53cf62b186b6 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -766,13 +766,17 @@ void * __init alloc_bootmem_section(unsigned long size,
unsigned long section_nr)
{
bootmem_data_t *bdata;
- unsigned long pfn, goal;
+ unsigned long pfn, goal, limit;
pfn = section_nr_to_pfn(section_nr);
goal = pfn << PAGE_SHIFT;
+ limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
- return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, 0);
+ if (goal + size > limit)
+ limit = 0;
+
+ return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
}
#endif