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[34.48.33.21]) by smtp.gmail.com with UTF8SMTPSA id 00721157ae682-7952a1d9b38sm80237017b3.27.2026.02.08.18.39.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 08 Feb 2026 18:39:38 -0800 (PST) Date: Sun, 08 Feb 2026 21:39:38 -0500 From: Willem de Bruijn To: Jakub Kicinski , davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, shuah@kernel.org, willemb@google.com, petrm@nvidia.com, donald.hunter@gmail.com, michael.chan@broadcom.com, pavan.chebbi@broadcom.com, linux-kselftest@vger.kernel.org, Jakub Kicinski Message-ID: In-Reply-To: <20260207003509.3927744-7-kuba@kernel.org> References: <20260207003509.3927744-1-kuba@kernel.org> <20260207003509.3927744-7-kuba@kernel.org> Subject: Re: [PATCH net-next v2 6/9] selftests: drv-net: gro: use SO_TXTIME to schedule packets together Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Jakub Kicinski wrote: > Longer packet sequence tests are quite flaky when the test is run > over a real network. Try to avoid at least the jitter on the sender > side by scheduling all the packets to be sent at once using SO_TXTIME. > Use hardcoded tx time of 5msec in the future. In my test increasing > this time past 2msec makes no difference so 5msec is plenty of margin. > Since we now expect more output buffering make sure to raise SNDBUF. > > Experimenting with long sequences I see frequent failures when sending > 200 packets, only 50-100 packets get coalesced. With this change > up to 1000 packets get coalesced relatively reliably. > > Reviewed-by: Petr Machata > Signed-off-by: Jakub Kicinski Does this require having FQ installed? I don't see any qdisc config in the GRO test.