Re: [PATCH v2 3/4] selftests: net: udpgso_bench: Fix racing bug between the rx/tx programs
From: Willem de Bruijn <willemb@google.com>
Date: 2023-01-31 13:34:22
Also in:
linux-kselftest, lkml
On Tue, Jan 31, 2023 at 8:06 AM Andrei Gherzan [off-list ref] wrote:
"udpgro_bench.sh" invokes udpgso_bench_rx/udpgso_bench_tx programs subsequently and while doing so, there is a chance that the rx one is not ready to accept socket connections. This racing bug could fail the test with at least one of the following: ./udpgso_bench_tx: connect: Connection refused ./udpgso_bench_tx: sendmsg: Connection refused ./udpgso_bench_tx: write: Connection refused This change addresses this by making udpgro_bench.sh wait for the rx program to be ready before firing off the tx one - with an exponential back off algorithm from 1s to 10s. Signed-off-by: Andrei Gherzan <redacted>
please CC: reviewers of previous revisions on new revisions also for upcoming patches: please clearly mark net or net-next.
quoted hunk ↗ jump to hunk
--- tools/testing/selftests/net/udpgso_bench.sh | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)diff --git a/tools/testing/selftests/net/udpgso_bench.sh b/tools/testing/selftests/net/udpgso_bench.sh index dc932fd65363..20b5db8fcbde 100755 --- a/tools/testing/selftests/net/udpgso_bench.sh +++ b/tools/testing/selftests/net/udpgso_bench.sh@@ -7,6 +7,7 @@ readonly GREEN='\033[0;92m' readonly YELLOW='\033[0;33m' readonly RED='\033[0;31m' readonly NC='\033[0m' # No Color +readonly TESTPORT=8000 # Keep this in sync with udpgso_bench_rx/tx
then also pass explicit -p argument to the processes to keep all three consistent
quoted hunk ↗ jump to hunk
readonly KSFT_PASS=0 readonly KSFT_FAIL=1@@ -56,10 +57,27 @@ trap wake_children EXIT run_one() { local -r args=$@ + local -r init_delay_s=1 + local -r max_delay_s=10 + local delay_s=0 + local nr_socks=0 ./udpgso_bench_rx & ./udpgso_bench_rx -t & + # Wait for the above test program to get ready to receive connections. + delay_s="${init_delay_s}" + while [ "$delay_s" -lt "$max_delay_s" ]; do + nr_socks="$(ss -lnHi | grep -c "\*:${TESTPORT}")" + [ "$nr_socks" -eq 2 ] && break + sleep "$delay_s" + delay="$((delay*2))"
I don't think we need exponential back-off for something this simple
+ done
+ if [ "$nr_socks" -ne 2 ]; then
+ echo "timed out while waiting for udpgso_bench_rx"
+ exit 1
+ fi
+
./udpgso_bench_tx ${args}
}
--
2.34.1