From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?S3J6eXN6dG9mIE9sxJlkemtp?= Subject: Re: bnx2/BCM5709: why 5 interrupts on a 4 core system (2.6.33.3) Date: Tue, 18 May 2010 17:35:26 +0200 Message-ID: <4BF2B3BE.60209@ans.pl> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "netdev@vger.kernel.org" To: Michael Chan Return-path: Received: from bizon.gios.gov.pl ([195.187.34.71]:57583 "EHLO bizon.gios.gov.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756515Ab0ERPfc (ORCPT ); Tue, 18 May 2010 11:35:32 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 2010-05-16 20:51, Michael Chan wrote: > Krzysztof Oledzki wrote: > >> >> Why the driver registers 5 interrupts instead of 4? How to >> limit it to 4? >> > > The first vector (eth0-0) handles link interrupt and other slow > path events. It also has an RX ring for non-IP packets that are > not hashed by the RSS hash. The majority of the rx packets should > be hashed to the rx rings eth0-1 - eth0-4, so I would assign these > vectors to different CPUs. Did some more test on a two 4 core CPUs (8 CPUs reported to the system)= =20 and on a two 4 core CPUs with HT (16 CPUs reported to the system) and i= n=20 both cases there are 8 instead of 9 vectors: eth0-0 .. eth0-7 (irqs 61=20 =2E. 68). However, dmesg shows that 9 interrupts are allocated: bnx2 0000:01:00.0: irq 61 for MSI/MSI-X bnx2 0000:01:00.0: irq 62 for MSI/MSI-X bnx2 0000:01:00.0: irq 63 for MSI/MSI-X bnx2 0000:01:00.0: irq 64 for MSI/MSI-X bnx2 0000:01:00.0: irq 65 for MSI/MSI-X bnx2 0000:01:00.0: irq 66 for MSI/MSI-X bnx2 0000:01:00.0: irq 67 for MSI/MSI-X bnx2 0000:01:00.0: irq 68 for MSI/MSI-X bnx2 0000:01:00.0: irq 69 for MSI/MSI-X It such case, which ring will be used for slow path and non-IP packets=20 and why there is no additional queue like in a 4CPU case? Best regards, Krzysztof Ol=C4=99dzki