Am 03.01.22 um 19:57 schrieb John Stultz:
On Mon, Dec 27, 2021 at 1:52 AM guangming.cao@mediatek.com wrote:
From: Guangming Guangming.Cao@mediatek.com
Thanks for submitting this!
Add a size check for allcation since the allocation size is
nit: "allocation" above.
always less than the total DRAM size.
In general, it might be good to add more context to the commit message to better answer *why* this change is needed rather than what the change is doing. ie: What negative thing happens without this change? And so how does this change avoid or improve things?
Completely agree, just one little addition: Could you also add this why as comment to the code?
When we stumble over this five years from now it is absolutely not obvious why we do this.
Thanks, Christian.
Signed-off-by: Guangming Guangming.Cao@mediatek.com Signed-off-by: jianjiao zeng jianjiao.zeng@mediatek.com
v2: 1. update size limitation as total_dram page size. 2. update commit message
drivers/dma-buf/dma-heap.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 56bf5ad01ad5..e39d2be98d69 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -55,6 +55,8 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, struct dma_buf *dmabuf; int fd;
if (len / PAGE_SIZE > totalram_pages())return -EINVAL;This seems sane. I know ION used to have some 1/2 of memory cap to avoid unnecessary memory pressure on crazy allocations.
Could you send again with an improved commit message?
thanks -john