From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-3.sys.kth.se (smtp-3.sys.kth.se [130.237.48.192]) by dpdk.org (Postfix) with ESMTP id 6844558F6 for ; Mon, 5 Nov 2018 10:01:09 +0100 (CET) Received: from smtp-3.sys.kth.se (localhost.localdomain [127.0.0.1]) by smtp-3.sys.kth.se (Postfix) with ESMTP id 22D4444B1; Mon, 5 Nov 2018 10:01:09 +0100 (CET) X-Virus-Scanned: by amavisd-new at kth.se Received: from smtp-3.sys.kth.se ([127.0.0.1]) by smtp-3.sys.kth.se (smtp-3.sys.kth.se [127.0.0.1]) (amavisd-new, port 10024) with LMTP id CwHISDv5OS_o; Mon, 5 Nov 2018 10:01:08 +0100 (CET) Received: from exdb02.ug.kth.se (unknown [192.168.32.112]) by smtp-3.sys.kth.se (Postfix) with ESMTPS id 68478449D; Mon, 5 Nov 2018 10:01:04 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kth.se; s=default; t=1541408468; bh=Kf+Zqzci3QsFkv6USwOnnN3flcyJcKwK5pxyWntbVT4=; h=From:To:CC:Subject:Date:References:In-Reply-To; b=loWqLBNIO6JoaI7wrMq6lupHVxy2AKUSlsgncypyNApcCmhYKQfvT5m98kSxjjS3p +2fmqgcY2zaEnymUvjZkdeHdVRdY0HXvZTxeV5S6xABw08RYbFJLXv1cflq2LKrGa2 uOQDEJdx9cXjdFCjdqzaRvmSE9PSyygGs9FtXbAA= Received: from exdb06.ug.kth.se (192.168.32.116) by exdb02.ug.kth.se (192.168.32.112) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 5 Nov 2018 10:01:03 +0100 Received: from exdb05.ug.kth.se (192.168.32.115) by exdb06.ug.kth.se (192.168.32.116) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 5 Nov 2018 10:01:03 +0100 Received: from exdb05.ug.kth.se ([192.168.32.115]) by exdb05.ug.kth.se ([192.168.32.115]) with mapi id 15.00.1367.000; Mon, 5 Nov 2018 10:01:03 +0100 From: Tom Barbette To: Shahaf Shuler , "dev@dpdk.org" , Ferruh Yigit , Thomas Monjalon , Andrew Rybchenko , "olivier.matz@6wind.com" CC: Yongseok Koh Thread-Topic: [PATCH v4] mlx5: Support for rte_eth_rx_queue_count Thread-Index: AQHUbgdDPtmLhezfi0WmV0F+xn+z/KU0VsIAgAS5ceuAAWoAgIAGb2OY Date: Mon, 5 Nov 2018 09:01:03 +0000 Message-ID: <1541408462940.66979@kth.se> References: <1540653055-67051-1-git-send-email-barbette@kth.se>, <1540976475938.69727@kth.se>, In-Reply-To: Accept-Language: fr-FR, sv-SE, en-US Content-Language: fr-FR X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [130.237.20.142] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v4] mlx5: Support for rte_eth_rx_queue_count X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Nov 2018 09:01:09 -0000 =0A= > It will tell you if in a given offset on the rxq you have a packet ready.= I think it will fit your needs, see below.=0A= So we just loose in precision here. We're looking at ML techniques that wil= l play better with a numerical value and benefit from more entropy than arb= itrarily poking of some thresholds.=0A= If one had to remain, I'd say rx_descriptor_* should be removed as it can b= e deduced from queue_count. Moreover, in the MLX5 case, calling the functio= n 3 times to get "half busy", "partially busy" or "idle" will lead to scann= ing the queue 3 times...=0A= =0A= > But for the latency it is better to work w/ NIC host coherent clock + tim= estamps (like you implemented on a different patch).=0A= We're looking at both as you noticed. But timestamping is much more costly.= Hence latency is more for monitoring, reporting to the operator, while que= ue statistics are used for scheduling. It's harder to understand a latency = value as a higher latency may only mean that a bunch of packets were more c= omplex to handle. But we want to look at the relation between the two.=0A= =0A= I think this patch should go in (with maybe a solution for vectorized?). An= d when the removal of queue_count will be discussed I'll follow. But I'm su= re other people will jump in the discussion at that time.=0A= =0A= Thanks for your time anyway,=0A= Tom=