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 | 7 +++++++
1 files changed, 7 insertions(+)
diff --git a/mm/slab.c b/mm/slab.c
index 4cbf8bb..5a782ff 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1454,7 +1454,14 @@ static void *kmem_getpages(struct kmem_c
int i;
flags |= cachep->gfpflags;
+#ifndef CONFIG_MMU
+ /* nommu uses slab's for process anonymous memory allocations, so
+ * requires __GFP_COMP to properly refcount higher order allocations"
+ */
+ page = alloc_pages_node(nodeid, (flags | __GFP_COMP), cachep->gfporder);
+#else
page = alloc_pages_node(nodeid, flags, cachep->gfporder);
+#endif
if (!page)
return NULL;
addr = page_address(page);
--
Best regards,
Luke Yang, Kernel for Blackfin maintainer
[email protected]