From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) by dpdk.org (Postfix) with ESMTP id 9A06A98 for ; Tue, 28 Aug 2018 18:01:47 +0200 (CEST) Received: by mail-pf1-f182.google.com with SMTP id b11-v6so922427pfo.3 for ; Tue, 28 Aug 2018 09:01:47 -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=1DIZ3BkDqIevvtW5xaZ3slqxz0f7zgdPUfBhLQ8VVrk=; b=IWdDc1DEo2AtkfXWlwIvdjP3cPCTZPsEIH9Df/yxr8D6pOGrVjPjihuV5YGPHxjw/H YCvQtGu5q1qzZcyysKuonRxYBIkpyJXyK4FxdlOYAS9v0nzT9C0UMs3EmxmZ7SMNBAnd Uiua8Cya8hcE0RIW2A1nwSdByzc9mg3Y+vIzD0aiiUBQ7QqNS6YmKul3jX4piSkaGTvq 7Bb+Mhy0q0tVNykahy8Q6c+O/QMpojhPnozQyyPRFVbS1MNaG/IEYQ8hXnGcGSkJob5m C3oVMN2R+d5SLxTWgR5mw1xxIq6NQ3er0slSsvyOd5p+TvZePw/FDDMQZzhXfyVrn3nR sCxw== 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=1DIZ3BkDqIevvtW5xaZ3slqxz0f7zgdPUfBhLQ8VVrk=; b=RsAwNYP/ioE1kfblyAUpuZtWg37RDOqC1TaCtf8I7BOb2svec+h191tKyue6L+UXcD aCl9AvPDpL4LyluUrBTpHWLwgl+P9pZkO7t+PVbXBpdYmRqANf3/MpP0OdkxILGl1Bvw 1iSYal4+7tN8emsL10A83AFBI5LwF26bnfkMU9kBZnBVcKyHyN52zX7HGF0batPt/sKE dSkf0iNXgyrTZVA6XUhIY9EPAcCvDcJpprUBWBmDFWJWZmNC6wkR1vFarGhsSsEuos61 SGHkyAF7R41YtzV5aS0x46VA7r83X5Z31q8v0V18+DlNFG1k9jZN14tXWxR8ilwAJB6Q skoQ== X-Gm-Message-State: APzg51A8FGVWt5NXQNUfAUsshdakA4toUCDCzD/tN1I0pO+iOPwtLlao s6YADk3f7efZVDe367IIasQAMg== X-Google-Smtp-Source: ANB0VdY0OBhGH6ugpaeshC81B/n6D1NYW7XU+ds02tXbjrw/2QeEPfK4cRxCSZLSB8c8LWFyEyth3w== X-Received: by 2002:a62:f40a:: with SMTP id r10-v6mr2215480pff.47.1535472105302; Tue, 28 Aug 2018 09:01:45 -0700 (PDT) Received: from shemminger-XPS-13-9360 ([167.220.98.61]) by smtp.gmail.com with ESMTPSA id g66-v6sm2828771pfk.39.2018.08.28.09.01.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 28 Aug 2018 09:01:45 -0700 (PDT) Date: Tue, 28 Aug 2018 09:01:42 -0700 From: Stephen Hemminger To: Saber Rezvani Cc: dev@dpdk.org Message-ID: <20180828090142.1262c5ea@shemminger-XPS-13-9360> In-Reply-To: <74400e6a-91ba-3648-0980-47ceae1089a7@zoho.com> References: <74400e6a-91ba-3648-0980-47ceae1089a7@zoho.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] IXGBE throughput loss with 4+ cores 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: Tue, 28 Aug 2018 16:01:47 -0000 On Tue, 28 Aug 2018 17:34:27 +0430 Saber Rezvani wrote: > Hi, > > > I have run multi_process/symmetric_mp example in DPDK example directory. > For a one process its throughput is line rate but as I increase the > number of cores I see decrease in throughput. For example, If the number > of queues set to 4 and each queue assigns to a single core, then the > throughput will be something about 9.4. if 8 queues, then throughput > will be 8.5. > > I have read the following, but it was not convincing. > > http://mails.dpdk.org/archives/dev/2015-October/024960.html > > > I am eagerly looking forward to hearing from you, all. > > > Best wishes, > > Saber > > Not completely surprising. If you have more cores than packet line rate then the number of packets returned for each call to rx_burst will be less. With large number of cores, most of the time will be spent doing reads of PCI registers for no packets!