From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756119AbZAJWil (ORCPT ); Sat, 10 Jan 2009 17:38:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754022AbZAJWic (ORCPT ); Sat, 10 Jan 2009 17:38:32 -0500 Received: from relay3.sgi.com ([192.48.171.31]:60577 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753985AbZAJWic (ORCPT ); Sat, 10 Jan 2009 17:38:32 -0500 Message-Id: <20090110223819.033438000@polaris-admin.engr.sgi.com> References: <20090110223818.459493000@polaris-admin.engr.sgi.com> User-Agent: quilt/0.46-1 Date: Sat, 10 Jan 2009 14:38:22 -0800 From: Mike Travis To: Ingo Molnar Cc: Rusty Russell , Yinghai Lu , Jack Steiner , linux-kernel@vger.kernel.org Subject: [PATCH 4/4] kstat: modify kstat_irqs_legacy to be variable sized Content-Disposition: inline; filename=var-kstat-irqs Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: reduce memory usage. Allocate kstat_irqs_legacy based on nr_cpu_ids to deal with this memory usage bump when NR_CPUS bumped from 128 to 4096: 8192 +253952 262144 +3100% kstat_irqs_legacy(.bss) This is only when CONFIG_SPARSE_IRQS=y. Signed-off-by: Mike Travis --- kernel/irq/handle.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- linux-2.6-for-ingo.orig/kernel/irq/handle.c +++ linux-2.6-for-ingo/kernel/irq/handle.c @@ -124,8 +124,7 @@ static struct irq_desc irq_desc_legacy[N } }; -/* FIXME: use bootmem alloc ...*/ -static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS]; +static unsigned int *kstat_irqs_legacy; int __init early_irq_init(void) { @@ -146,9 +145,13 @@ int __init early_irq_init(void) /* allocate irq_desc_ptrs array based on nr_irqs */ irq_desc_ptrs = alloc_bootmem(nr_irqs * sizeof(void *)); + /* allocate based on nr_cpu_ids */ + kstat_irqs_legacy = alloc_bootmem(NR_IRQS_LEGACY * nr_cpu_ids * + sizeof(int)); + for (i = 0; i < legacy_count; i++) { desc[i].irq = i; - desc[i].kstat_irqs = kstat_irqs_legacy[i]; + desc[i].kstat_irqs = kstat_irqs_legacy + i * NR_IRQS_LEGACY; lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); init_alloc_desc_masks(&desc[i], 0, true); irq_desc_ptrs[i] = desc + i; --