2006-03-31 02:11:46

by Luke Yang

[permalink] [raw]
Subject: [PATCH] Fix mm regression bug: nommu use compound page in slab allocator

Hi all,

The earlier patch to consolidate mmu and nommu page allocation
and refcounting by using compound pages for nommu allocations
had a bug: kmalloc slabs who's pages were initially allocated
by a non-__GFP_COMP allocator could be passed into mm/nommu.c
kmalloc allocations which really wanted __GFP_COMP underlying
pages. Fix that by having nommu pass __GFP_COMP to all higher order
slab allocations.

Thanks Nick!

Signed-off-by: Luke Yang <[email protected]>
Acked-by: Nick Piggin <[email protected]>

slab.c | 4 ++++
1 files changed, 4 insertions(+)

diff --git a/mm/slab.c b/mm/slab.c
index 4cbf8bb..388a6a9 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1454,7 +1454,11 @@ static void *kmem_getpages(struct kmem_c
int i;

flags |= cachep->gfpflags;
+#ifdef CONFIG_MMU
page = alloc_pages_node(nodeid, flags, cachep->gfporder);
+#else
+ page = alloc_pages_node(nodeid, (flags | __GFP_COMP), cachep->gfporder);
+#endif
if (!page)
return NULL;
addr = page_address(page);

--
Best regards,
Luke Yang, Kernel for Blackfin maintainer
[email protected]


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nommu_use_compound_page_in_slab.patch (430.00 B)
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