From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752087Ab2LSHWU (ORCPT ); Wed, 19 Dec 2012 02:22:20 -0500 Received: from smtp.wow.synacor.com ([64.8.70.55]:40210 "EHLO smtp.mail.wowway.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514Ab2LSHWN (ORCPT ); Wed, 19 Dec 2012 02:22:13 -0500 X-Spam-Rating: None X_CMAE_Category: 0,0 Undefined,Undefined X-CNFS-Analysis: v=1.1 cv=1OiOQyls0DfDlMA8Ql3WVUwqY/YbKV4zTodrIVDIeHY= c=1 sm=0 a=nDghuxUhq_wA:10 a=kj9zAlcOel0A:10 a=alHIm3v4SGykTGcX2CUA:9 a=CjuIK1q_8ugA:10 a=zsaeSSr3pazHFAQJU9uUyg==:117 X-CM-Score: 0 Authentication-Results: smtp02.wow.synacor.com smtp.mail=set@squish.homelinux.org; spf=neutral Date: Wed, 19 Dec 2012 02:22:11 -0500 From: Paul Thompson To: Grant Likely Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: SPARSE_IRQ Message-ID: <20121219072211.GE2939@squish.home.loc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi; Perhaps Im being an idiot, but it looks to me like the menu-item for SPARSE_IRQ (under General setup -> IRQ subsystem) depends solely on MAY_HAVE_SPARSE_IRQ, but I only see *one* user for that in the kernel now, the SuperH arch (arch/sh/Kconfig). It looks like everyone else explicitly sets SPARSE_IRQ. However the menu-items description implies it is a more generic option... It seems like this menu item used to appear, in a forced on state, then this condition made it disapear, leaving a blank IRQ subsystem menu for me. I was trying to work around that, but now, I am not sure exactly what is supposed to be going on here... Paul (from kernel/irq/Kconfig) config SPARSE_IRQ bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ ---help--- Sparse irq numbering is useful for distro kernels that want to define a high CONFIG_NR_CPUS value but still want to have low kernel memory footprint on smaller machines. ( Sparse irqs can also be beneficial on NUMA boxes, as they spread out the interrupt descriptors in a more NUMA-friendly way. ) If you don't know what to do here, say N.