From patchwork Sun Jan 31 11:14:03 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Blanchard X-Patchwork-Id: 44109 X-Patchwork-Delegate: benh@kernel.crashing.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id ACF6BB8894 for ; Sun, 31 Jan 2010 22:15:54 +1100 (EST) Received: by ozlabs.org (Postfix, from userid 1010) id AC88AB7D63; Sun, 31 Jan 2010 22:15:26 +1100 (EST) Date: Sun, 31 Jan 2010 22:14:03 +1100 From: Anton Blanchard To: benh@kernel.crashing.org Subject: [PATCH 5/5] powerpc: Increase NR_IRQS Kconfig maximum to 32768 Message-ID: <20100131111403.GP2996@kryten> References: <20100131110938.GL2996@kryten> <20100131111012.GM2996@kryten> <20100131111155.GN2996@kryten> <20100131111315.GO2996@kryten> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20100131111315.GO2996@kryten> User-Agent: Mutt/1.5.20 (2009-06-14) Cc: linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org With dynamic irq descriptors the overhead of a large NR_IRQS is much lower than it used to be. With more MSI-X capable adapters and drivers exploiting multiple vectors we may as well allow the user to increase it beyond the current maximum of 512. 32768 seems large enough that we'd never have to bump it again (although I bet my prediction is horribly wrong). It boot tests OK and the vmlinux footprint increase is only around 500kB due to: struct irq_map_entry irq_map[NR_IRQS]; We format /proc/interrupts correctly with the previous changes: CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 286: 0 0 0 0 0 0 516: 0 0 0 0 0 0 16689: 1833 0 0 0 0 0 17157: 0 0 0 0 0 0 17158: 319 0 0 0 0 0 25092: 0 0 0 0 0 0 Signed-off-by: Anton Blanchard Index: linux-cpumask/arch/powerpc/Kconfig =================================================================== --- linux-cpumask.orig/arch/powerpc/Kconfig 2010-01-31 15:07:11.707211107 +1100 +++ linux-cpumask/arch/powerpc/Kconfig 2010-01-31 21:52:39.999711689 +1100 @@ -58,7 +58,7 @@ config IRQ_PER_CPU config NR_IRQS int "Number of virtual interrupt numbers" - range 32 512 + range 32 32768 default "512" help This defines the number of virtual interrupt numbers the kernel