From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by dpdk.org (Postfix) with ESMTP id 0500A4C9D for ; Fri, 31 Aug 2018 22:09:41 +0200 (CEST) Received: by mail-pl1-f182.google.com with SMTP id x6-v6so5926754plv.10 for ; Fri, 31 Aug 2018 13:09:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=uBr192OOYqHPRm13XyYo+9le+Et0KmpIEGO4flCsZZA=; b=m6JGk/3hh5vKfu+3gkIvFDz8ggiMvivnC9yrmGdZZwVEX9POPJZBEs7xTSrwvrWCVC sQaF17e5aZ3evptDmtq/OASdTbTZtXs/GxgrUlKKkrqp6yWvXdj7Gv3zIHEDoFZrAAiD V7QZzUcihe1E0pwJ03hyp7DLMwDX3VNtdI1Qy0oo+CH/Cqnnt8V5EnrOTaB8ZtryGFA7 30wQCcqTqwNwgckZpD9fnp27vRtjlLFV5ZqQbpGINvAIDda90sUtgV8CDz7B5kbOY7l5 GfMTH+1fj6PUVD5zGWJ2YBXydyAGKBJ2x8rhzKyDCDzC7WiW3xmvVYHc6nkO4OAzL77v lG7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=uBr192OOYqHPRm13XyYo+9le+Et0KmpIEGO4flCsZZA=; b=VSFpGL5tSh8ZoJg+Y2Pa9DaaJsZg4IoGxV6rLrHZWoZgTZBbomt6F06XlqzAzGiGof kV0Zm7zIjbbnEaz/kIdz8108NWpHKxhVK4gZlW5IW+0na279TcA06XuggfiguJ7bepXg /6Fc5rs7BayM6kj/u5CldpKeXtsIntf5l+cRBUsEaAMmQf9bi02yaTQdAvJX+6TGF0cF ovFdmVdglO0ls7X78OBhl0cZ4SKE27/Er6ck8dXirfybnYrgznkzNVRhurebhcMH4h/q 3R8wamz4RABuNaJ53HqbnjBiacnLyJ6EMijXgryOIk5T8q9+10cQUT1bBWNm6Lq4BLOE lb3A== X-Gm-Message-State: APzg51ArvnT84iAKsOoKQRAdBGIN5ln6Et3Tcul8oQbVfbKzN/h+z811 WzLB7NoV+ox/m+HjcY/4ndRgLV+0ilKkfA== X-Google-Smtp-Source: ANB0Vdasd0WM3EMiZLu+JU9FIiwyGcfavjiFA4U9mdlRX8249xoSoVKs9RDC+8iTCrLd7ZVxvZsy3g== X-Received: by 2002:a17:902:b189:: with SMTP id s9-v6mr16969887plr.188.1535746180171; Fri, 31 Aug 2018 13:09:40 -0700 (PDT) Received: from xeon-e3 (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id d19-v6sm15345779pgi.50.2018.08.31.13.09.39 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 31 Aug 2018 13:09:40 -0700 (PDT) Date: Fri, 31 Aug 2018 13:09:33 -0700 From: Stephen Hemminger To: Sungho Hong Cc: users@dpdk.org Message-ID: <20180831130933.699f9f39@xeon-e3> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-users] low performance of send and receiving single message in RTE_RING X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Aug 2018 20:09:41 -0000 On Fri, 31 Aug 2018 12:55:22 -0700 Sungho Hong wrote: > Hello, DPDK-users, > > I am wondering whether there is a good explanation for high latency caused > by rte_ring when testing the round-trip latency using 1 burst in (tx rx > queue). > > I have tested the performance using two nodes (client and server) > and calculated the elapsed latency of the round-trip of single pingpong. > The latency is calculated on two different test-cases > 1. elapsed latency of send and receive directly from rx tx queue. > 2. elapsed latency of send and receive from rte_ring. > > > Latency with direct tx rx queue with 1 burst > When I send a single messages (512, 1024, 4096 bytes) (1 burst for each > request) and receive 1 burst of response from the remote server. > the latency is approximately 4 ~ 8 microseconds. > > > RTE_RING Latency with 1 burst > When I use rte_ring to send and receive data from client and server, the > latency increases like crazy which is 59 microseconds to 100 microseconds. > > > RTE_RING Latency with 10 bursts > When I use bursts for example (10 messages per request) > and calculate the elapsed latency by dividing the total elapsed time with > the total ping-pong messages (total-latency)/(total ping-pong received > messages). > I could get a very good performance using rte_ring 7 ~ 10 microseconds. > > > I was wondering whether someone can tell me what I should look at in order > to decrease the latency of RTE_RING. > Because even though I don't use multiple bursts, the latency should be low. The ring itself should have no visible latency. It comes down to how the producer and consumer are signaling each other and process scheduling.