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Tsirkin" To: Jiri Pirko 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: <20240516150101-mutt-send-email-mst@kernel.org> References: <20240510072431-mutt-send-email-mst@kernel.org> <20240515041909-mutt-send-email-mst@kernel.org> <20240516083100-mutt-send-email-mst@kernel.org> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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. -- MST