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| author | Magnus Karlsson <magnus.karlsson@intel.com> | 2020-09-10 10:31:05 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-09-14 18:38:11 -0700 |
| commit | 5a2a0dd88f0f267ac5953acd81050ae43a82201f (patch) | |
| tree | b24ffa24309ba95a3e56b962a90d9fd17226a194 /samples | |
| parent | 3131cf66d3033aa40db5b5d72a2673315b61c862 (diff) | |
| download | lwn-5a2a0dd88f0f267ac5953acd81050ae43a82201f.tar.gz lwn-5a2a0dd88f0f267ac5953acd81050ae43a82201f.zip | |
samples/bpf: Fix possible deadlock in xdpsock
Fix a possible deadlock in the l2fwd application in xdpsock that can
occur when there is no space in the Tx ring. There are two ways to get
the kernel to consume entries in the Tx ring: calling sendto() to make
it send packets and freeing entries from the completion ring, as the
kernel will not send a packet if there is no space for it to add a
completion entry in the completion ring. The Tx loop in l2fwd only
used to call sendto(). This patches adds cleaning the completion ring
in that loop.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1599726666-8431-3-git-send-email-magnus.karlsson@gmail.com
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/xdpsock_user.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index b6175cb9a31d..b60bf4ef7cdb 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1125,6 +1125,7 @@ static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds) while (ret != rcvd) { if (ret < 0) exit_with_error(-ret); + complete_tx_l2fwd(xsk, fds); if (xsk_ring_prod__needs_wakeup(&xsk->tx)) kick_tx(xsk); ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx); |