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Tsirkin" Cc: Jason Wang , netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, xuanzhuo@linux.alibaba.com, virtualization@lists.linux.dev, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com Subject: Re: [patch net-next] virtio_net: add support for Byte Queue Limits Message-ID: References: <20240510072431-mutt-send-email-mst@kernel.org> <20240515041909-mutt-send-email-mst@kernel.org> <20240516083100-mutt-send-email-mst@kernel.org> <20240516150101-mutt-send-email-mst@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240516150101-mutt-send-email-mst@kernel.org> Thu, May 16, 2024 at 09:04:41PM CEST, mst@redhat.com wrote: >On Thu, May 16, 2024 at 05:25:20PM +0200, Jiri Pirko wrote: >> >> >I'd expect a regression if any to be in a streaming benchmark. >> >> Can you elaborate? > >BQL does two things that can hurt throughput: >- limits amount of data in the queue - can limit bandwidth > if we now get queue underruns >- adds CPU overhead - can limit bandwidth if CPU bound > >So checking result of a streaming benchmark seems important. I understand. Didn't see any degradation in TCP_STREAM netperf. But I will try to extend the testing. Thanks! > > >-- >MST >