Messages in this thread Patch in this message | | | Subject | Re: WARNING: at mm/page_alloc.c:1159 get_page_from_freelist+0x325/0x655() | From | Catalin Marinas <> | Date | Wed, 17 Jun 2009 13:11:17 +0100 |
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On Wed, 2009-06-17 at 13:31 +0200, Ingo Molnar wrote: > a new warning started popping up today, in the new page allocator > code. The allocation came from kmemleak: > > WARNING: at mm/page_alloc.c:1159 get_page_from_freelist+0x325/0x655() > Hardware name: System Product Name > Modules linked in: > Pid: 4367, comm: ifup Not tainted 2.6.30-tip-04303-g5ada65e-dirty #54431 > Call Trace: > [<ffffffff810dba73>] ? get_page_from_freelist+0x325/0x655 > [<ffffffff8106f140>] warn_slowpath_common+0x88/0xcb > [<ffffffff8106f1a5>] warn_slowpath_null+0x22/0x38 > [<ffffffff810dba73>] get_page_from_freelist+0x325/0x655 > [<ffffffff810dc18c>] __alloc_pages_nodemask+0x14c/0x5b0 > [<ffffffff811063e1>] ? deactivate_slab+0xce/0x16b > [<ffffffff8103b1c8>] ? native_sched_clock+0x40/0x79 > [<ffffffff811063e1>] ? deactivate_slab+0xce/0x16b > [<ffffffff811063e1>] ? deactivate_slab+0xce/0x16b > [<ffffffff81102417>] alloc_pages_current+0xcc/0xeb > [<ffffffff81107a78>] alloc_slab_page+0x2a/0x7e > [<ffffffff81107b27>] new_slab+0x5b/0x210 > [<ffffffff811063fa>] ? deactivate_slab+0xe7/0x16b > [<ffffffff81108253>] __slab_alloc+0x214/0x3da > [<ffffffff8110f58d>] ? kmemleak_alloc+0x83/0x35a > [<ffffffff8110f58d>] ? kmemleak_alloc+0x83/0x35a > [<ffffffff8110863c>] kmem_cache_alloc+0xac/0x14e > [<ffffffff8110f58d>] kmemleak_alloc+0x83/0x35a > [<ffffffff812b6436>] ? cfq_get_queue+0x101/0x231 > [<ffffffff81108511>] kmem_cache_alloc_node+0xf8/0x177 > [<ffffffff812b6436>] ? cfq_get_queue+0x101/0x231 > [<ffffffff812b6436>] cfq_get_queue+0x101/0x231
Kmemleak needs to allocate memory for the pointer tracing and it currently passes the same gfp flags as those used by the original caller. In this case cfq_find_alloc_queue uses __GFP_NOFAIL.
The reason for this was to avoid GFP_ATOMIC if the caller wasn't requiring it. I think the approach below is better:
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 58ec86c..46c9c93 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -462,7 +462,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count, struct prio_tree_node *node; struct stack_trace trace; - object = kmem_cache_alloc(object_cache, gfp & ~GFP_SLAB_BUG_MASK); + object = kmem_cache_alloc(object_cache, gfp & (GFP_KERNEL | GFP_ATOMIC)); if (!object) { kmemleak_panic("kmemleak: Cannot allocate a kmemleak_object " "structure\n"); @@ -636,7 +636,7 @@ static void add_scan_area(unsigned long ptr, unsigned long offset, return; } - area = kmem_cache_alloc(scan_area_cache, gfp & ~GFP_SLAB_BUG_MASK); + area = kmem_cache_alloc(scan_area_cache, gfp & (GFP_KERNEL | GFP_ATOMIC)); if (!area) { kmemleak_warn("kmemleak: Cannot allocate a scan area\n"); goto out; -- Catalin
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