Re: [PATCH v2 4/4] selftests: net: udpgso_bench_tx: Cater for pending datagrams zerocopy benchmarking

On Tue, Jan 31, 2023 at 8:06 AM Andrei Gherzan andrei.gherzan@canonical.com wrote:

The test tool can check that the zerocopy number of completions value is valid taking into consideration the number of datagram send calls. This can catch the system into a state where the datagrams are still in the system (for example in a qdisk, waiting for the network interface to return a completion notification, etc).

This change adds a retry logic of computing the number of completions up to a configurable (via CLI) timeout (default: 2 seconds).

Signed-off-by: Andrei Gherzan andrei.gherzan@canonical.com

tools/testing/selftests/net/udpgso_bench_tx.c | 38 +++++++++++++++---- 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c index b47b5c32039f..5a29b5f24023 100644 --- a/tools/testing/selftests/net/udpgso_bench_tx.c +++ b/tools/testing/selftests/net/udpgso_bench_tx.c @@ -62,6 +62,7 @@ static int cfg_payload_len = (1472 * 42); static int cfg_port = 8000; static int cfg_runtime_ms = -1; static bool cfg_poll; +static int cfg_poll_loop_timeout_ms = 2000; static bool cfg_segment; static bool cfg_sendmmsg; static bool cfg_tcp; @@ -235,16 +236,17 @@ static void flush_errqueue_recv(int fd) } }

-static void flush_errqueue(int fd, const bool do_poll) +static void flush_errqueue(int fd, const bool do_poll,

•           unsigned long poll_timeout, const bool poll_err)
  

{ if (do_poll) { struct pollfd fds = {0}; int ret;

            fds.fd = fd;

•           ret = poll(&fds, 1, 500);
  

•           ret = poll(&fds, 1, poll_timeout);
            if (ret == 0) {
  

•                   if (cfg_verbose)
  

•                   if ((cfg_verbose) && (poll_err))
                            fprintf(stderr, "poll timeout\n");
            } else if (ret < 0) {
                    error(1, errno, "poll");
  

@@ -254,6 +256,22 @@ static void flush_errqueue(int fd, const bool do_poll) flush_errqueue_recv(fd); }

+static void flush_errqueue_retry(int fd, const bool do_poll, unsigned long num_sends) +{

•   unsigned long tnow, tstop;
  

•   bool first_try = true;
  

•   tnow = gettimeofday_ms();
  

•   tstop = tnow + cfg_poll_loop_timeout_ms;
  

•   do {
  

•           flush_errqueue(fd, do_poll, tstop - tnow, first_try);
  

•           first_try = false;
  

•           if (!do_poll)
  

•                   usleep(1000);  // a throttling delay if polling is enabled
  

never reached