On Fri, May 9, 2025 at 2:58 PM Song Liu <s...@kernel.org> wrote:
>
> 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.
Ok let me change up the name of the aliasing variable to local_udmabuf.
> [...]
>
> >
> > 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.
The caller does currently check to decide if it should bother running
the tests or not, and calls destroy_test_buffers() if not.
> > - 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
Will do, thanks.
