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[79.182.31.92]) by smtp.gmail.com with ESMTPSA id j15sm8366155wrx.69.2020.07.09.22.58.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2020 22:58:24 -0700 (PDT) Date: Fri, 10 Jul 2020 01:58:21 -0400 From: "Michael S. Tsirkin" To: Eugenio Perez Martin Cc: Jason Wang , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, kvm list , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: Re: [PATCH RFC v8 02/11] vhost: use batched get_vq_desc version Message-ID: <20200710015615-mutt-send-email-mst@kernel.org> References: <20200622122546-mutt-send-email-mst@kernel.org> <419cc689-adae-7ba4-fe22-577b3986688c@redhat.com> <0a83aa03-8e3c-1271-82f5-4c07931edea3@redhat.com> <20200709133438-mutt-send-email-mst@kernel.org> <7dec8cc2-152c-83f4-aa45-8ef9c6aca56d@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 10, 2020 at 07:39:26AM +0200, Eugenio Perez Martin wrote: > > > How about playing with the batch size? Make it a mod parameter instead > > > of the hard coded 64, and measure for all values 1 to 64 ... > > > > > > Right, according to the test result, 64 seems to be too aggressive in > > the case of TX. > > > > Got it, thanks both! In particular I wonder whether with batch size 1 we get same performance as without batching (would indicate 64 is too aggressive) or not (would indicate one of the code changes affects performance in an unexpected way). -- MST