On Thu, Jul 3, 2025 at 12:03 AM Stanislav Fomichev <stfomichev@xxxxxxxxx> wrote: > > On 07/02, Jason Xing wrote: > > From: Jason Xing <kernelxing@xxxxxxxxxxx> > > > > The subtest sends 33 packets at one time on purpose to see if xsk > > exitting __xsk_generic_xmit() updates the global consumer of tx queue > > when reaching the max loop (max_tx_budget, 32 by default). The number 33 > > can avoid xskq_cons_peek_desc() updates the consumer when it's about to > > quit sending, to accurately check if the issue that the first patch > > resolves remains. The new case will not check this issue in zero copy > > mode. > > > > Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx> > > --- > > v5 > > Link: https://lore.kernel.org/all/20250627085745.53173-1-kerneljasonxing@xxxxxxxxx/ > > 1. use the initial approach to add a new testcase > > 2. add a new flag 'check_consumer' to see if the check is needed > > --- > > tools/testing/selftests/bpf/xskxceiver.c | 51 +++++++++++++++++++++++- > > tools/testing/selftests/bpf/xskxceiver.h | 1 + > > 2 files changed, 51 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c > > index 0ced4026ee44..ed12a55ecf2a 100644 > > --- a/tools/testing/selftests/bpf/xskxceiver.c > > +++ b/tools/testing/selftests/bpf/xskxceiver.c > > @@ -109,6 +109,8 @@ > > > > #include <network_helpers.h> > > > > +#define MAX_TX_BUDGET_DEFAULT 32 > > + > > static bool opt_verbose; > > static bool opt_print_tests; > > static enum test_mode opt_mode = TEST_MODE_ALL; > > @@ -1091,11 +1093,45 @@ static bool is_pkt_valid(struct pkt *pkt, void *buffer, u64 addr, u32 len) > > return true; > > } > > > > +static u32 load_value(u32 *counter) > > +{ > > + return __atomic_load_n(counter, __ATOMIC_ACQUIRE); > > +} > > + > > +static bool kick_tx_with_check(struct xsk_socket_info *xsk, int *ret) > > +{ > > + u32 max_budget = MAX_TX_BUDGET_DEFAULT; > > + u32 cons, ready_to_send; > > + int delta; > > + > > + cons = load_value(xsk->tx.consumer); > > + ready_to_send = load_value(xsk->tx.producer) - cons; > > + *ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0); > > + > > + delta = load_value(xsk->tx.consumer) - cons; > > + /* By default, xsk should consume exact @max_budget descs at one > > + * send in this case where hitting the max budget limit in while > > + * loop is triggered in __xsk_generic_xmit(). Please make sure that > > + * the number of descs to be sent is larger than @max_budget, or > > + * else the tx.consumer will be updated in xskq_cons_peek_desc() > > + * in time which hides the issue we try to verify. > > + */ > > + if (ready_to_send > max_budget && delta != max_budget) > > + return false; > > + > > + return true; > > +} > > + > > static int kick_tx(struct xsk_socket_info *xsk) > > { > > int ret; > > > > - ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0); > > + if (xsk->check_consumer) { > > + if (!kick_tx_with_check(xsk, &ret)) > > + return TEST_FAILURE; > > + } else { > > + ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0); > > + } > > if (ret >= 0) > > return TEST_PASS; > > if (errno == ENOBUFS || errno == EAGAIN || errno == EBUSY || errno == ENETDOWN) { > > @@ -2613,6 +2649,18 @@ static int testapp_adjust_tail_grow_mb(struct test_spec *test) > > XSK_UMEM__LARGE_FRAME_SIZE * 2); > > } > > > > +static int testapp_tx_queue_consumer(struct test_spec *test) > > +{ > > + int nr_packets = MAX_TX_BUDGET_DEFAULT + 1; > > + > > + pkt_stream_replace(test, nr_packets, MIN_PKT_SIZE); > > + test->ifobj_tx->xsk->batch_size = nr_packets; > > + if (!(test->mode & TEST_MODE_ZC)) > > + test->ifobj_tx->xsk->check_consumer = true; > > The test looks good to me, thank you! Thanks. > > One question here: why not exit/return for TEST_MODE_ZC instead > of conditionally setting check_consumer? As you said, yes, we could skip the zc test for this testapp_tx_queue_consumer(). It doesn't affect the goal or result of the subtest. So do you expect me to respin this patch or just leave it as is? Thanks, Jason
