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authorHong zhi guo <honkiko@gmail.com>2012-07-31 16:41:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-31 18:42:39 -0700
commit92ca922f0a19145f2dcc99d84fe656fa55b52c2e (patch)
tree3d7e616ce15d79d44c1c21f16958978a211fc738
parentc2cddf991974a00aa7b40a21e829bc034b8199b6 (diff)
vmalloc: walk vmap_areas by sorted list instead of rb_next()
There's a walk by repeating rb_next to find a suitable hole. Could be simply replaced by walk on the sorted vmap_area_list. More simpler and efficient. Mutation of the list and tree only happens in pair within __insert_vmap_area and __free_vmap_area, under protection of vmap_area_lock. The patch code is also under vmap_area_lock, so the list walk is safe, and consistent with the tree walk. Tested on SMP by repeating batch of vmalloc anf vfree for random sizes and rounds for hours. Signed-off-by: Hong Zhiguo <honkiko@gmail.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/vmalloc.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e03f4c7307a..7e25ee3ce6e 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -413,11 +413,11 @@ nocache:
if (addr + size - 1 < addr)
goto overflow;
- n = rb_next(&first->rb_node);
- if (n)
- first = rb_entry(n, struct vmap_area, rb_node);
- else
+ if (list_is_last(&first->list, &vmap_area_list))
goto found;
+
+ first = list_entry(first->list.next,
+ struct vmap_area, list);
}
found: