Messages in this thread Patch in this message | | | Date | Tue, 20 Dec 2022 10:55:11 +0530 | From | Deepak R Varma <> | Subject | [PATCH] ARM/dma-mapping: use kvzalloc for fallback memory allocation need |
| |
When the memory sizes are not known upfront, it is preferred to use the kvzalloc helper function instead of direct conditional evaluation of size and kzalloc/vzalloc fallback design. The kvzalloc helper function in this case is more efficient as it avoids indefinite kzalloc retries when a small memory size is needed but is unavailable. This LWN article has further details on the advantages of using kvzalloc in case of fallback memory allocation needs: https://lwn.net/Articles/711653/
This patch proposal is based on following Coccinelle warning using the kvmalloc.cocci semantic patch.
arch/arm/mm/dma-mapping.c:858:28-29: WARNING opportunity for kvmalloc
Signed-off-by: Deepak R Varma <drv@mailo.com> --- Note: The patch proposal is compile tested only.
arch/arm/mm/dma-mapping.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index c135f6e37a00..2b79af377a81 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -855,10 +855,7 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, int i = 0; int order_idx = 0;
- if (array_size <= PAGE_SIZE) - pages = kzalloc(array_size, GFP_KERNEL); - else - pages = vzalloc(array_size); + pages = kvzalloc(array_size, GFP_KERNEL); if (!pages) return NULL;
-- 2.34.1
| |