Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756431AbZFWCaK (ORCPT ); Mon, 22 Jun 2009 22:30:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753365AbZFWC3u (ORCPT ); Mon, 22 Jun 2009 22:29:50 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:43480 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754293AbZFWC3t (ORCPT ); Mon, 22 Jun 2009 22:29:49 -0400 Date: Mon, 22 Jun 2009 19:29:18 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Benjamin Herrenschmidt cc: James Bottomley , Pekka Enberg , linux-kernel , "Rafael J. Wysocki" , Sachin Sant Subject: Re: [PATCH] mm/init: cpu_hotplug_init() must be initialized before SLAB In-Reply-To: <1245717089.4017.18.camel@pasglop> Message-ID: References: <1245717089.4017.18.camel@pasglop> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2388 Lines: 94 On Tue, 23 Jun 2009, Benjamin Herrenschmidt wrote: > + /* > + * This initializes the mutex used by get/put_online_cpus() > + * which is used by SLAB > + */ > + cpu_hotplug_init(); Oh fudge it. Why not get rid of that stupid thing, rather than have that subtle dependency and a comment for it. IOW, does this simpler alternative also work? When given the choice of simplifying and removing code, always do so. Static initializers are much nicer than having to worry about when something gets initialized, no? Linus --- include/linux/cpu.h | 5 ----- init/main.c | 1 - kernel/cpu.c | 13 +++++-------- 3 files changed, 5 insertions(+), 14 deletions(-) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 2643d84..4d668e0 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -69,7 +69,6 @@ static inline void unregister_cpu_notifier(struct notifier_block *nb) int cpu_up(unsigned int cpu); void notify_cpu_starting(unsigned int cpu); -extern void cpu_hotplug_init(void); extern void cpu_maps_update_begin(void); extern void cpu_maps_update_done(void); @@ -84,10 +83,6 @@ static inline void unregister_cpu_notifier(struct notifier_block *nb) { } -static inline void cpu_hotplug_init(void) -{ -} - static inline void cpu_maps_update_begin(void) { } diff --git a/init/main.c b/init/main.c index 09131ec..4870dfe 100644 --- a/init/main.c +++ b/init/main.c @@ -678,7 +678,6 @@ asmlinkage void __init start_kernel(void) #endif page_cgroup_init(); enable_debug_pagealloc(); - cpu_hotplug_init(); kmemtrace_init(); kmemleak_init(); debug_objects_mem_init(); diff --git a/kernel/cpu.c b/kernel/cpu.c index 395b697..8ce1004 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -34,14 +34,11 @@ static struct { * an ongoing cpu hotplug operation. */ int refcount; -} cpu_hotplug; - -void __init cpu_hotplug_init(void) -{ - cpu_hotplug.active_writer = NULL; - mutex_init(&cpu_hotplug.lock); - cpu_hotplug.refcount = 0; -} +} cpu_hotplug = { + .active_writer = NULL, + .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), + .refcount = 0, +}; #ifdef CONFIG_HOTPLUG_CPU -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/