On Fri, May 9, 2025 at 2:43 PM T.J. Mercier <tjmerc...@google.com> wrote:
>
[...]
> >
> > Personally, I would prefer we just merge all the logic of
> > create_udmabuf() and create_sys_heap_dmabuf()
> > into create_test_buffers().
>
> That's a lot of different stuff to put in one place. How about
> returning file descriptors from the buffer create functions while
> having them clean up after themselves:
I do like this version better. Some nitpicks though.
>
> -static int memfd, udmabuf;
> +static int udmabuf;
About this, and ...
> static const char udmabuf_test_buffer_name[DMA_BUF_NAME_LEN] =
> "udmabuf_test_buffer_for_iter";
> static size_t udmabuf_test_buffer_size;
> static int sysheap_dmabuf;
> static const char sysheap_test_buffer_name[DMA_BUF_NAME_LEN] =
> "sysheap_test_buffer_for_iter";
> static size_t sysheap_test_buffer_size;
>
> -static int create_udmabuf(int map_fd)
> +static int create_udmabuf(void)
> {
> struct udmabuf_create create;
> - int dev_udmabuf;
> - bool f = false;
> + int dev_udmabuf, memfd, udmabuf;
.. here.
It is not ideal to have a global udmabuf and a local udmabuf.
If we want the global version, let's rename the local one.
[...]
>
> static int create_test_buffers(int map_fd)
> {
> - int ret;
> + bool f = false;
> +
> + udmabuf = create_udmabuf();
> + sysheap_dmabuf = create_sys_heap_dmabuf();
>
> - ret = create_udmabuf(map_fd);
> - if (ret)
> - return ret;
> + if (udmabuf < 0 || sysheap_dmabuf < 0)
> + return -1;
We also need destroy_test_buffers() on the error path here,
or at the caller.
>
> - return create_sys_heap_dmabuf(map_fd);
> + return bpf_map_update_elem(map_fd, udmabuf_test_buffer_name,
> &f, BPF_ANY) ||
> + bpf_map_update_elem(map_fd, sysheap_test_buffer_name,
> &f, BPF_ANY);
> }
>
> static void destroy_test_buffers(void)
> {
> close(udmabuf);
> - close(memfd);
> close(sysheap_dmabuf);
For the two global fds, let's reset them to -1 right after close().
Thanks,
Song
