Messages in this thread Patch in this message | | | Subject | [RFC/PATCH v2] mm: Introduce GFP_PANIC for non-failing allocations | From | Pekka Enberg <> | Date | Fri, 08 May 2009 15:57:28 +0300 |
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From: Cyrill Gorcunov <gorcunov@openvz.org>
This patch introduces a GFP_PANIC flag that can be used as an annotation that a call to kmalloc() or alloc_pages() is expected to never fail. This is useful in early boot code, for example.
To save one GFP flag bit, use a combination of __GFP_NOFAIL, __GFP_NOREPEAT, and __GFP_NOMEMALLOC to make sure we always end up in the "nopage" path of the page allocator if an allocation fails.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> --- Yes, this is totally untested and needs to be rebased on top of -mm.
include/linux/gfp.h | 1 + mm/page_alloc.c | 3 +++ 2 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 0bbc15f..c7c8a63 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -70,6 +70,7 @@ struct vm_area_struct; #define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \ __GFP_HARDWALL | __GFP_HIGHMEM | \ __GFP_MOVABLE) +#define GFP_PANIC (__GFP_NOFAIL | __GFP_NORETRY | __GFP_NOMEMALLOC) #ifdef CONFIG_NUMA #define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e2f2699..4b062e5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1670,6 +1670,9 @@ nopage: dump_stack(); show_mem(); } + if (unlikely(gfp_mask & GFP_PANIC)) + panic("Out of memory: %s order: %d, gfp_mask:0x%x\n", + p->comm, order, gfp_mask); got_pg: return page; } -- 1.5.6.3
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