lib/stackdepot.c: use __GFP_NOWARN for stack allocations

This (large, atomic) allocation attempt can fail.  We expect and handle
that, so avoid the scary warning.

Link: http://lkml.kernel.org/r/[email protected]
Cc: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

lib/stackdepot.c

@@ -242,6 +242,7 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
 		 */
 		alloc_flags &= ~GFP_ZONEMASK;
 		alloc_flags &= (GFP_ATOMIC | GFP_KERNEL);
+		alloc_flags |= __GFP_NOWARN;
 		page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER);
 		if (page)
 			prealloc = page_address(page);