From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by dpdk.org (Postfix) with ESMTP id 655098DA4 for ; Thu, 1 Oct 2015 11:59:50 +0200 (CEST) Received: by wiclk2 with SMTP id lk2so20422495wic.1 for ; Thu, 01 Oct 2015 02:59:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-type :content-transfer-encoding; bh=CV25r5v0e87FguIKnl4p5adcg9Qvxyf1HJSGf8Rob/4=; b=iewhuYQKVtzZwuwfOL3NfLcCsiI4ARsLS5f1T3WYQEJ3ZOF1oPu/vsgERUbJ+VLxP1 0uXrxLXD4owvLSAPoem2ZMs3B/j7bXcYY3c6d0cSLGCSl7BRiS+N7r8CJJZEtPm/6EzC wQlzpPbpNKCeOpMm20nfeG4OYrFeSqyEQgOnA3pQQREhEd28fUtez1w+B3DN2KWwjwa6 fmdd96PA4BiItUTMuIZvNZ3Jo4sQS3vx7XRtzbwaQIFm8Q7Ty1Izwkk/sNAdZRoh0s6b FmuAQleft34saZbniriNnuUTokJtfh/je3A2rFCTnsudFOW3ZhHCFGG1uZJI26wIiqF1 ZV3g== X-Gm-Message-State: ALoCoQnmBoAqmkV+S9EvjDc9DpHca8NcGpbuxp9HreftNlBcV4b9UjpqJZKVRaaqdoV8Ef7Dcl/O X-Received: by 10.194.192.6 with SMTP id hc6mr9124951wjc.33.1443693590151; Thu, 01 Oct 2015 02:59:50 -0700 (PDT) Received: from avi.cloudius ([37.142.229.250]) by smtp.googlemail.com with ESMTPSA id f17sm5255602wjn.38.2015.10.01.02.59.47 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Oct 2015 02:59:48 -0700 (PDT) To: "Michael S. Tsirkin" References: <560BDE24.8000308@scylladb.com> <20150930165359-mutt-send-email-mst@redhat.com> <560BF782.4070308@scylladb.com> <20150930175848-mutt-send-email-mst@redhat.com> <560C0171.7080507@scylladb.com> <20150930204016.GA29975@redhat.com> <20151001113828-mutt-send-email-mst@redhat.com> <560CF44A.60102@scylladb.com> <20151001120027-mutt-send-email-mst@redhat.com> <560CFB66.5050904@scylladb.com> <20151001124211-mutt-send-email-mst@redhat.com> From: Avi Kivity Message-ID: <560D0413.5080401@scylladb.com> Date: Thu, 1 Oct 2015 12:59:47 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20151001124211-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance 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, 01 Oct 2015 09:59:50 -0000 On 10/01/2015 12:55 PM, Michael S. Tsirkin wrote: > On Thu, Oct 01, 2015 at 12:22:46PM +0300, Avi Kivity wrote: >> It's easy to claim that >> a solution is around the corner, only no one was looking for it, but the >> reality is that kernel bypass has been a solution for years for high >> performance users, > I never said that it's trivial. > > It's probably a lot of work. It's definitely more work than just abusing > sysfs. > > But it looks like a write system call into an eventfd is about 1.5 > microseconds on my laptop. Even with a system call per packet, system > call overhead is not what makes DPDK drivers outperform Linux ones. > 1.5 us = 0.6 Mpps per core limit. dpdk performance is in the tens of millions of packets per system. It's not just the lack of system calls, of course, the architecture is completely different.