On Thu, Jan 05, 2017 at 07:40:10PM +0900, Tetsuo Handa wrote:

On 2017/01/04 23:20, Michal Hocko wrote:

quoted

OK, so I've checked the open coded implementations and converted most of
them. There are few which are either confused and need some special
handling or need double checking.

diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
index cf2cbc211d83..9dc0f0ff0321 100644
--- a/drivers/md/bcache/util.h
+++ b/drivers/md/bcache/util.h

@@ -44,10 +44,7 @@ struct closure;
 	(heap)->size = (_size);						\
 	_bytes = (heap)->size * sizeof(*(heap)->data);			\
 	(heap)->data = NULL;						\
-	if (_bytes < KMALLOC_MAX_SIZE)					\
-		(heap)->data = kmalloc(_bytes, (gfp));			\
-	if ((!(heap)->data) && ((gfp) & GFP_KERNEL))			\
-		(heap)->data = vmalloc(_bytes);				\
+	(heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
 	(heap)->data;							\
 })
 

@@ -138,10 +135,7 @@ do {									\
 	(fifo)->front = (fifo)->back = 0;				\
 	(fifo)->data = NULL;						\
 									\
-	if (_bytes < KMALLOC_MAX_SIZE)					\
-		(fifo)->data = kmalloc(_bytes, (gfp));			\
-	if ((!(fifo)->data) && ((gfp) & GFP_KERNEL))			\
-		(fifo)->data = vmalloc(_bytes);				\
+	(fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
 	(fifo)->data;							\
 })

These macros are doing strange checks.
((gfp) & GFP_KERNEL) means any bit in GFP_KERNEL is set.
((gfp) & GFP_KERNEL) == GFP_KERNEL might make sense. Actually,
all callers seems to be passing GFP_KERNEL to these macros.

Kent, how do you want to correct this? You want to apply
a patch that removes gfp argument before applying this patch?
Or, you want Michal to directly overwrite by this patch?

Michal, "(fifo)->data = NULL;" line will become redundant
and "(gfp) & GFP_KERNEL" will become "GFP_KERNEL".

Please just go ahead and replace all that crap with a single call to kvmalloc().

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