dma-buf: system_heap: do not warn for costly allocation

Linux VM is not hard to support PAGE_ALLOC_COSTLY_ODER allocation
so normally expects driver passes __GFP_NOWARN in that case
if they has fallback options.

system_heap in dmabuf is the case so do not flood into demsg
with the warning for recording more precious information logs.
(below is ION warning example I got but dmabuf system heap is
nothing different).

[ 1233.911533][  T460] warn_alloc: 11 callbacks suppressed
[ 1233.911539][  T460] allocator@2.0-s: page allocation failure: order:4, mode:0x140dc2(GFP_HIGHUSER|__GFP_COMP|__GFP_ZERO), nodemask=(null),cpuset=/,mems_allowed=0
[ 1233.926235][  T460] Call trace:
[ 1233.929370][  T460]  dump_backtrace+0x0/0x1d8
[ 1233.933704][  T460]  show_stack+0x18/0x24
[ 1233.937701][  T460]  dump_stack+0xc0/0x140
[ 1233.941783][  T460]  warn_alloc+0xf4/0x148
[ 1233.945862][  T460]  __alloc_pages_slowpath+0x9fc/0xa10
[ 1233.951101][  T460]  __alloc_pages_nodemask+0x278/0x2c0
[ 1233.956285][  T460]  ion_page_pool_alloc+0xd8/0x100
[ 1233.961144][  T460]  ion_system_heap_allocate+0xbc/0x2f0
[ 1233.966440][  T460]  ion_buffer_create+0x68/0x274
[ 1233.971130][  T460]  ion_buffer_alloc+0x8c/0x110
[ 1233.975733][  T460]  ion_dmabuf_alloc+0x44/0xe8
[ 1233.980248][  T460]  ion_ioctl+0x100/0x320
[ 1233.984332][  T460]  __arm64_sys_ioctl+0x90/0xc8
[ 1233.988934][  T460]  el0_svc_common+0x9c/0x168
[ 1233.993360][  T460]  do_el0_svc+0x1c/0x28
[ 1233.997358][  T460]  el0_sync_handler+0xd8/0x250
[ 1234.001989][  T460]  el0_sync+0x148/0x180

Signed-off-by: Minchan Kim <minchan@kernel.org>

drivers/dma-buf/heaps/system_heap.c

@@ -40,7 +40,7 @@ struct dma_heap_attachment {
 	bool mapped;
 };
 
-#define HIGH_ORDER_GFP  (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
+#define HIGH_ORDER_GFP  (((GFP_HIGHUSER | __GFP_ZERO \
 				| __GFP_NORETRY) & ~__GFP_RECLAIM) \
 				| __GFP_COMP)
 #define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO | __GFP_COMP)
@@ -315,6 +315,7 @@ static struct page *alloc_largest_available(unsigned long size,
 					    unsigned int max_order)
 {
 	struct page *page;
+	unsigned long gfp_flags;
 	int i;
 
 	for (i = 0; i < NUM_ORDERS; i++) {
@@ -323,7 +324,11 @@ static struct page *alloc_largest_available(unsigned long size,
 		if (max_order < orders[i])
 			continue;
 
-		page = alloc_pages(order_flags[i], orders[i]);
+		gfp_flags = order_flags[i];
+		if (orders[i] > PAGE_ALLOC_COSTLY_ORDER)
+			gfp_flags |= __GFP_NOWARN;
+
+		page = alloc_pages(gfp_flags, orders[i]);
 		if (!page)
 			continue;
 		return page;