Re: [PATCH bpf-next] selftests/bpf: Accept unnamed dma-bufs in the dmabuf_iter default test
From: Qiliang Yuan
Date: Fri Oct 09 2026 - 22:53:10 EST
On Fri, Oct 9, 2026 at 5:07 PM T.J. Mercier <tjmercier@xxxxxxxxxx> wrote:
> Hi Qiliang, are you running this locally instead of with:
> tools/testing/selftests/bpf/vmtest.sh -- ./test_progs?
Yes, I ran ./test_progs directly in a Debian testing VM, not through
vmtest.sh. The VM runs a GNOME desktop on virtio-gpu, and gnome-shell,
mutter-x11-frames and ibus-x11 each hold a 4 KiB udmabuf without a name
(their fdinfo shows exp_name udmabuf and no name line). As the
iterator walks every dma-buf in the system, default_iter fails on such
a machine before it gets to the two buffers it created. The minimal VM
of vmtest.sh has no such buffers, so it doesn't show up there.
The subtest only checks its own two buffers, so skipping over the name
of any other buffer seemed safer than relying on all of them having
one.
Thanks,
Qiliang