From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Merav Sicron" Subject: Re: [net-next patch v2] bnx2x: Add run-time CNIC support Date: Tue, 10 Jul 2012 15:17:00 +0300 Message-ID: <1341922620.27284.16.camel@lb-tlvb-meravs.il.broadcom.com> References: <1341828055-4467-1-git-send-email-meravs@broadcom.com> <20120709.141010.996787793429264956.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, eilong@broadcom.com, dmitry@broadcom.com To: "David Miller" Return-path: Received: from mms1.broadcom.com ([216.31.210.17]:4201 "EHLO mms1.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754775Ab2GJMSO (ORCPT ); Tue, 10 Jul 2012 08:18:14 -0400 In-Reply-To: <20120709.141010.996787793429264956.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2012-07-09 at 14:10 -0700, David Miller wrote: > From: "Merav Sicron" > Date: Mon, 9 Jul 2012 13:00:55 +0300 > > > - max_non_def_sbs = bnx2x_get_num_non_def_sbs(pdev); > > + cnic_enabled = IS_ENABLED(CONFIG_CNIC) ? 1 : 0; > > This, as I said, it pointless. > > Every distribution is going to turn on this Kconfig option so guarding > this at all using the Kconfig option is largely valueless. > There are still two advantages in disabling CNIC in bnx2x: Saving resources (MSI-X vector and memory) as well as reducing some latency. When the HW is configured to storage-offload (rather than NIC-only mode) it does connection search over the PCI, which is additional 0.5usec - 2.5usec, depending on the system load. When CNIC is not enabled, the HW is configured to eliminate the search. While it is true that distributions enable the CNIC Kconfig option, some users that care about resources and latency compile a kernel without it. Can you please re-consider this patch? Thanks, Merav