[dpdk-stable] [PATCH 2/2] app/testpmd: fix weak RSS hash key for flow

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

The default RSS hash key automatically provided by testpmd for RSS actions
specified without one is so weak that traffic can't spread properly on L4
with it (as seen with TCPv6).

It is only 30 bytes long, zero-padded to RSS_HASH_KEY_LENGTH (64 bytes),
later truncated to 40 bytes for most PMDs. The presence of padding is
really what kills balancing.

This patch provides a full 64-byte (non-zero-terminated) string to address
this issue.

Fixes: d0ad8648b1c5 ("app/testpmd: fix RSS flow action configuration")
Cc: stable@dpdk.org

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
 app/test-pmd/cmdline_flow.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
index f4ea0a5cf..9918d7fda 100644
--- a/app/test-pmd/cmdline_flow.c
+++ b/app/test-pmd/cmdline_flow.c
@@ -2772,7 +2772,8 @@ parse_vc_action_rss(struct context *ctx, const struct token *token,
 			.key = action_rss_data->key,
 			.queue = action_rss_data->queue,
 		},
-		.key = "testpmd's default RSS hash key",
+		.key = "testpmd's default RSS hash key, "
+			"override it for better balancing",
 		.queue = { 0 },
 	};
 	for (i = 0; i < action_rss_data->conf.queue_num; ++i)
-- 
2.11.0