On Thu, Dec 10, 2020 at 5:03 PM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
>
> On 12/10/20 4:36 PM, Magnus Karlsson wrote:
> > From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> >
> > Fix a possible hang in xdpsock that can occur when using multiple
> > threads. In this case, one or more of the threads might get stuck in
> > the while-loop in tx_only after the user has signaled the main thread
> > to stop execution. In this case, no more Tx packets will be sent, so a
> > thread might get stuck in the aforementioned while-loop. Fix this by
> > introducing a test inside the while-loop to check if the benchmark has
> > been terminated. If so, exit the loop.
> >
> > Fixes: cd9e72b6f210 ("samples/bpf: xdpsock: Add option to specify batch size")
> > Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
>
> With the patch applied, I'm getting a new warning:
>
> CC /home/darkstar/trees/bpf-next/samples/bpf/xdpsock_user.o
> /home/darkstar/trees/bpf-next/samples/bpf/xdpsock_user.c: In function ‘main’:
> /home/darkstar/trees/bpf-next/samples/bpf/xdpsock_user.c:1272:6: warning: ‘idx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> 1272 | u32 idx;
> | ^~~
Sorry, I get it too. It was just masked with the other warnings I get
these days when compiling the bpf samples. Regardless, it is the
compiler trying to tell me I have done something stupid :-(. It should
really be a return instead of a break, sigh. Will send a v2.
> Previously compiling w/o issues:
>
> [...]
> CC /home/darkstar/trees/bpf-next/samples/bpf/xdpsock_ctrl_proc.o
> CC /home/darkstar/trees/bpf-next/samples/bpf/xdpsock_user.o
> CC /home/darkstar/trees/bpf-next/samples/bpf/xsk_fwd.o
> LD /home/darkstar/trees/bpf-next/samples/bpf/fds_example
> [...]
>
> For testing, I used:
>
> gcc --version
> gcc (GCC) 9.0.1 20190312 (Red Hat 9.0.1-0.10)
>
> Ptal, thx!
