From: Willem de Bruijn <willemdebruijn.kernel@gmail•com>
To: Jakub Kicinski <kuba@kernel•org>, davem@davemloft•net
Cc: netdev@vger•kernel.org, edumazet@google•com, pabeni@redhat•com,
andrew+netdev@lunn•ch, horms@kernel•org,
Jakub Kicinski <kuba@kernel•org>,
willemb@google•com, anubhavsinggh@google•com,
mohsin.bashr@gmail•com, shuah@kernel•org,
linux-kselftest@vger•kernel.org
Subject: Re: [PATCH net-next] selftests: drv-net: gro: increase the rcvbuf size
Date: Wed, 07 Jan 2026 18:51:38 -0500 [thread overview]
Message-ID: <willemdebruijn.kernel.191adb8734bbb@gmail.com> (raw)
In-Reply-To: <20260107232557.2147760-1-kuba@kernel.org>
Jakub Kicinski wrote:
> The gro.py test (testing software GRO) is slightly flaky when
> running against fbnic. We see one flake per roughly 20 runs in NIPA,
> mostly in ipip.large, and always including some EAGAIN:
>
> # Shouldn't coalesce if exceed IP max pkt size: Test succeeded
> # Expected {65475 899 }, Total 2 packets
> # Received {65475 899 }, Total 2 packets.
> # Expected {64576 900 900 }, Total 3 packets
> # Received {64576 /home/virtme/testing/wt-24/tools/testing/selftests/drivers/net/gro: could not receive: Resource temporarily unavailable
>
> The test sends 2 large frames (64k + change). Looks like the default
> packet socket rcvbuf (~200kB) may not be large enough to hold them.
> Bump the rcvbuf to 1MB.
>
> Add a debug print showing socket statistics to make debugging this
> issue easier in the future. Without the rcvbuf increase we see:
>
> # Shouldn't coalesce if exceed IP max pkt size: Test succeeded
> # Expected {65475 899 }, Total 2 packets
> # Received {65475 899 }, Total 2 packets.
> # Expected {64576 900 900 }, Total 3 packets
> # Received {64576 Socket stats: packets=7, drops=3
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> # /home/virtme/testing/wt-24/tools/testing/selftests/drivers/net/gro: could not receive: Resource temporarily unavailable
>
> Signed-off-by: Jakub Kicinski <kuba@kernel•org>
Reviewed-by: Willem de Bruijn <willemb@google•com>
next prev parent reply other threads:[~2026-01-07 23:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-07 23:25 [PATCH net-next] selftests: drv-net: gro: increase the rcvbuf size Jakub Kicinski
2026-01-07 23:51 ` Willem de Bruijn [this message]
2026-01-10 1:40 ` patchwork-bot+netdevbpf
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