[PATCH] dma/pool: eliminate CMA alloc warning in atomic_pool_expand

[PATCH] dma/pool: eliminate CMA alloc warning in atomic_pool_expand

[Maximilian Heyne]

atomic_pool_expand() allocates with decreasing page order first from the
CMA and if that fails via alloc_pages(). If the cma allocation fails a
warning, such as the following, is printed:

  cma: __cma_alloc_frozen: reserved: alloc failed, req-size: 4096 pages, ret: -16
  cma: number of available pages:
  cma: range 0: 1024@0
  cma:
  => 1024 free of 1024 total pages
  DMA: preallocated 262144 KiB GFP_KERNEL pool for atomic allocations

In this case the allocation succeeded via alloc_pages and therefore,
printing the warning is not necessary. Therefore, similar to commit
463d439becb8 ("dma/pool: eliminate alloc_pages warning in
atomic_pool_expand") silence the warning also for the CMA attempt.

Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone")
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
---
 kernel/dma/pool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 00f422a1e8966..aa44fd74db538 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -99,7 +99,7 @@ static int atomic_pool_expand(struct dma_gen_pool *dma_pool, size_t pool_size,
 		pool_size = 1 << (PAGE_SHIFT + order);
 		if (cma_in_zone(gfp))
 			page = dma_alloc_from_contiguous(NULL, 1 << order,
-							 order, false);
+							 order, true);
 		if (!page)
 			page = alloc_pages(gfp | __GFP_NOWARN, order);
 	} while (!page && order-- > 0);
-- 
2.50.1

Re: [PATCH] dma/pool: eliminate CMA alloc warning in atomic_pool_expand

[Marek Szyprowski]

On 30.10.2026 11:00, Maximilian Heyne wrote:
> atomic_pool_expand() allocates with decreasing page order first from the
> CMA and if that fails via alloc_pages(). If the cma allocation fails a
> warning, such as the following, is printed:
>
>   cma: __cma_alloc_frozen: reserved: alloc failed, req-size: 4096 pages, ret: -16
>   cma: number of available pages:
>   cma: range 0: 1024@0
>   cma:
>   => 1024 free of 1024 total pages
>   DMA: preallocated 262144 KiB GFP_KERNEL pool for atomic allocations
>
> In this case the allocation succeeded via alloc_pages and therefore,
> printing the warning is not necessary. Therefore, similar to commit
> 463d439becb8 ("dma/pool: eliminate alloc_pages warning in
> atomic_pool_expand") silence the warning also for the CMA attempt.
>
> Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone")
> Signed-off-by: Maximilian Heyne <mheyne@amazon.de>

Applied to dma-mapping-for-next. Thanks!

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland