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.