From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by dpdk.org (Postfix) with ESMTP id F0EA830E for ; Fri, 31 May 2013 19:00:29 +0200 (CEST) Received: by mail-pd0-f173.google.com with SMTP id v14so2504690pde.32 for ; Fri, 31 May 2013 10:00:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding :x-gm-message-state; bh=tvhLdmGuoi4ogmkTzweMaYm86BXMj9du8XcWYTFxAYY=; b=R5KIJ+D444ogGNufIRx5HfpgvHoG8GSt2/H7FaHmNan2k3S369lx6SfkRmte0Qmknj 27jvVgingzxdp01GMxqVBoC46UaDhjlgFvAlwQsRg7RQE1Tyvl1DeiBOutBRdBbpV8Zz 241wmo+iedV/sxWl4Mgjtys+yiQ9ss3q52YOiXnFhSktDNhZ7KabXK+dvkYI94HdWw1A bSm3+w4DvWw5A1s9qnxh51HZivlYc1OU3KmYPRZIddAPGSDOfgUEwcwNtywkp+HdHgjx jrI2dgRxJlzmu4PoNogXbOvSrfUbXjRTpIgwoNeYZ72iqKMbYS8Pa2RZByQ7fbebGsCi pVbQ== X-Received: by 10.66.0.66 with SMTP id 2mr11713427pac.176.1370019636198; Fri, 31 May 2013 10:00:36 -0700 (PDT) Received: from nehalam.linuxnetplumber.net (static-50-53-71-109.bvtn.or.frontiernet.net. [50.53.71.109]) by mx.google.com with ESMTPSA id do4sm47444556pbc.8.2013.05.31.10.00.35 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 31 May 2013 10:00:35 -0700 (PDT) Date: Fri, 31 May 2013 10:00:32 -0700 From: Stephen Hemminger To: Damien Millescamps Message-ID: <20130531100032.0f4cb799@nehalam.linuxnetplumber.net> In-Reply-To: <51A8D353.50101@6wind.com> References: <20130530171234.301927271@vyatta.com> <51A86D65.2090003@6wind.com> <20130531084529.5c63d4c0@nehalam.linuxnetplumber.net> <51A8D353.50101@6wind.com> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Gm-Message-State: ALoCoQmW/ibjaybH1FfOa1CZ6pVOUNYaXVM6vimKVVcscpllEruV/c4eV+FXYX0u8S5zGWW8iRA5 Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH 0/7] Vyatta patches 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: Fri, 31 May 2013 17:00:30 -0000 On Fri, 31 May 2013 18:44:03 +0200 Damien Millescamps wrote: > On 05/31/2013 05:45 PM, Stephen Hemminger wrote: > > This was confirmed by several kernel developers including Andi Kleen from > > Intel. The value in /proc/cpuinfo comes from the APCI tables and is the value > > reported by the BIOS. There are machines that report socket 1 and 2. > > Haven't played with older kernels, but the topology information in sysfs > > has existed since 2.6.16. > Hi Stephen, > > You didn't really address my point, because the Linux documentation says > something doesn't mean it works in the real world. > > If you take the example of the hugepages, they have been in the Linux > kernel since 2.6.28, but the last fix was pushed in 2.6.37 and before > 2.6.33 it is just impossible to do something with hugepages. > If you take a look at section 2.3.2 of the DPDK getting started: > http://www.intel.com/content/dam/www/public/us/en/documents/guides/intel-dpdk-getting-started-guide.pdf, > you will find that this issue is at least partially addressed. > > So the point is that the topology information being theoretically > correct on all kernel Linux supported by the DPDK, but the information > being practically wrong on versions prior to kernel 3.3 means that the > "fix" is breaking the support for a quite huge range of kernel versions... > So maybe there might be a better way to get this node information on all > kernel still currently supported by the DPDK. > > Cheers, I will just state what we saw. /proc/cpuinfo was wrong on several Dell machines but sysfs is correct. And since are working on a product, not generic DPDK, there is no motivation to work on older kernels. I can dig out the email back and forth with the kernel developers to show that /proc/cpuinfo is not intended to report anything useful for NUMA related API if you want.