From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?S3J6eXN6dG9mIE9sxJlkemtp?= Subject: Re: [RFC] bnx2x: Insane RX rings Date: Thu, 09 Sep 2010 23:21:01 +0200 Message-ID: <4C894FBD.2020109@ans.pl> References: <1284065105.4782.11.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev , Eilon Greenstein To: Eric Dumazet Return-path: Received: from bizon.gios.gov.pl ([195.187.34.71]:42136 "EHLO bizon.gios.gov.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753658Ab0IIVVI (ORCPT ); Thu, 9 Sep 2010 17:21:08 -0400 In-Reply-To: <1284065105.4782.11.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On 2010-09-09 22:45, Eric Dumazet wrote: > So I have a small dev machine, 4GB of ram, > a dual E5540 cpu (quad core, 2 threads per core), > so a total of 16 threads. > > Two ethernet ports, eth0 and eth1, > > 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM577= 11E 10Gigabit PCIe > 02:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM577= 11E 10Gigabit PCIe > > bnx2x 0000:02:00.0: eth0: using MSI-X IRQs: sp 68 fp[0] 69 ... fp[1= 5] 84 > bnx2x 0000:02:00.1: eth1: using MSI-X IRQs: sp 85 fp[0] 86 ... fp[1= 5] 101 > > > Default configuration : > > ethtool -g eth0 > Ring parameters for eth0: > Pre-set maximums: > RX: 4078 > RX Mini: 0 > RX Jumbo: 0 > TX: 4078 > Current hardware settings: > RX: 4078 > RX Mini: 0 > RX Jumbo: 0 > TX: 4078 > > Problem is : With 16 RX queues per device , thats 4078*16*2Kbytes per > ethernet port. > > Total : > > skbuff_head_cache 130747 131025 256 15 1 : tunables 120 60= 8 : slabdata 8735 8735 40 > size-2048 130866 130888 2048 2 1 : tunables 24 12= 8 : slabdata 65444 65444 28 > > Thats about 300 Mbytes of memory, just in case some network trafic wi= ll occur. > > Lets do something about that ? Yep, it is ~8MB per queue, not so much alone, but a lot together. For=20 this reason I use something like bnx2.num_queues=3D2 on servers where I= =20 don't need much CPU power for network workload. Best regards, Krzysztof Ol=C4=99dzki