[PATCH net] selftests: net: cope with slow env in gro.sh test

[Paolo Abeni <pabeni@xxxxxxxxxx>]

The gro self-tests sends the packets to be aggregated with
multiple write operations.

When running is slow environment, it's hard to guarantee that
the GRO engine will wait for the last packet in an intended
train.

The above causes almost deterministic failures in our CI for
the 'large' test-case.

Address the issue explicitly ignoring failures for such case
in slow environments (KSFT_MACHINE_SLOW==true).

Fixes: 7d1575014a63 ("selftests/net: GRO coalesce test")
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
---
Note that the fixes tag is there mainly to justify targeting the net
tree, and this is aiming at net to hopefully make the test more stable
ASAP for both trees.

I experimented with a largish refactory replacing the multiple writes
with a single GSO packet, but exhausted by time budget before reaching
any good result.
---
 tools/testing/selftests/net/gro.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/net/gro.sh b/tools/testing/selftests/net/gro.sh
index 19352f106c1d..114b5281a3f5 100755
--- a/tools/testing/selftests/net/gro.sh
+++ b/tools/testing/selftests/net/gro.sh
@@ -31,6 +31,10 @@ run_test() {
       1>>log.txt
     wait "${server_pid}"
     exit_code=$?
+    if [ ${test} == "large" -a -n "${KSFT_MACHINE_SLOW}" ]; then
+        echo "Ignoring errors due to slow environment" 1>&2
+        exit_code=0
+    fi
     if [[ "${exit_code}" -eq 0 ]]; then
         break;
     fi
-- 
2.43.0