From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com [209.85.212.173]) by dpdk.org (Postfix) with ESMTP id EAAD8C69A for ; Thu, 25 Jun 2015 17:46:32 +0200 (CEST) Received: by wicnd19 with SMTP id nd19so168019972wic.1 for ; Thu, 25 Jun 2015 08:46:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=Pg9wp+6XDvXhUgT8HhFe2kqg0Ir9Fs44E25IPjhy8hc=; b=G9GoinoWjw+ZbqusT29t/4WYbG1hJzpEPqR8gQ5iP/GWwx9yjA9Mr91nBwgUe71vfb CGQihvmmlSZO57iHGtt6GBB70YJqc0aXlYnosz1e8q/2oHAxcJ62BCr9/EXThLjdPFS8 Tu4owClF0d9hSYfPQje4rfVfIhuBqw9ZvkevPvAUMrgizLEI3cj1xfNWPzlWPXDOIycW g6lzpsEeQOVhI6VYJyFPQ0h/UvEK2WIqs7NoV+YnOP2o0YcY9TtJPKoEv8waoZmZHn7N Te991hkvFTXHIQXwR/JGe0NAgbCjZ4TaPEoLzslitdR5EiwFZVLylfbpOEHC9ZPshhaK xIFw== X-Gm-Message-State: ALoCoQmX38rjg6lIiRNHKJH6P9q2uAQkG4MOVbOi/KxT5rYldYq9ORxFg00pD1hRcZYYf8vOz0SL X-Received: by 10.180.208.7 with SMTP id ma7mr7126512wic.0.1435247192691; Thu, 25 Jun 2015 08:46:32 -0700 (PDT) Received: from avi.cloudius ([212.143.139.214]) by mx.google.com with ESMTPSA id wi1sm46441990wjb.41.2015.06.25.08.46.30 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jun 2015 08:46:31 -0700 (PDT) Message-ID: <558C2256.4070802@cloudius-systems.com> Date: Thu, 25 Jun 2015 18:46:30 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Matthew Hall , "Vass, Sandor (Nokia - HU/Budapest)" References: <792CF0A6B0883C45AF8C719B2ECA946E42B2430F@DEMUMBX003.nsn-intra.net> <20150625151834.GA29296@mhcomputing.net> In-Reply-To: <20150625151834.GA29296@mhcomputing.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] VMXNET3 on vmware, ping delay X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 Jun 2015 15:46:33 -0000 On 06/25/2015 06:18 PM, Matthew Hall wrote: > On Thu, Jun 25, 2015 at 09:14:53AM +0000, Vass, Sandor (Nokia - HU/Budapest) wrote: >> According to my understanding each packet should go >> through BR as fast as possible, but it seems that the rte_eth_rx_burst >> retrieves packets only when there are at least 2 packets on the RX queue of >> the NIC. At least most of the times as there are cases (rarely - according >> to my console log) when it can retrieve 1 packet also and sometimes only 3 >> packets can be retrieved... > By default DPDK is optimized for throughput not latency. Try a test with > heavier traffic. > > There is also some work going on now for DPDK interrupt-driven mode, which > will work more like traditional Ethernet drivers instead of polling mode > Ethernet drivers. > > Though I'm not an expert on it, there is also a series of ways to optimize for > latency, which hopefully some others could discuss... or maybe search the > archives / web site / Intel tuning documentation. > What would be useful is a runtime switch between polling and interrupt modes. This was if the load is load you use interrupts, and as mitigation, you switch to poll mode, until the load drops again.