[PATCH 2/2] dmabuf/heaps: implement DMA_BUF_IOCTL_RW_FILE for system_heap

[Christian König]

On 5/15/25 16:03, wangtao wrote:
> [wangtao] My Test Configuration (CPU 1GHz, 5-test average):
> Allocation: 32x32MB buffer creation
> - dmabuf 53ms vs. udmabuf 694ms (10X slower)
> - Note: shmem shows excessive allocation time

Yeah, that is something already noted by others as well. But that is orthogonal.

> 
> Read 1024MB File:
> - dmabuf direct 326ms vs. udmabuf direct 461ms (40% slower)
> - Note: pin_user_pages_fast consumes majority CPU cycles
> 
> Key function call timing: See details below. 

Those aren't valid, you are comparing different functionalities here.

Please try using udmabuf with sendfile() as confirmed to be working by T.J.

Regards,
Christian.