Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756278Ab3IJA03 (ORCPT ); Mon, 9 Sep 2013 20:26:29 -0400 Received: from g5t0007.atlanta.hp.com ([15.192.0.44]:10779 "EHLO g5t0007.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756253Ab3IJA01 (ORCPT ); Mon, 9 Sep 2013 20:26:27 -0400 From: Toshi Kani To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, rjw@sisk.pl, kosaki.motohiro@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, Toshi Kani Subject: [PATCH] cpu/mem hotplug: Add try_online_node() for cpu_up() Date: Mon, 9 Sep 2013 18:24:31 -0600 Message-Id: <1378772671-27280-1-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.8.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4330 Lines: 145 cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call mem_online_node() to put its node online if offlined and then call build_all_zonelists() to initialize the zone list. These steps are specific to memory hotplug, and should be managed in mm/memory_hotplug.c. lock_memory_hotplug() should also be held for the whole steps. For this reason, this patch replaces mem_online_node() with try_online_node(), which performs the whole steps with lock_memory_hotplug() held. try_online_node() is named after try_offline_node() as they have similar purpose. There is no functional change in this patch. Signed-off-by: Toshi Kani --- include/linux/memory_hotplug.h | 8 +++++++- kernel/cpu.c | 29 +++-------------------------- mm/memory_hotplug.c | 15 +++++++++++++-- 3 files changed, 23 insertions(+), 29 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index dd38e62..22203c2 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -94,6 +94,8 @@ extern void __online_page_set_limits(struct page *page); extern void __online_page_increment_counters(struct page *page); extern void __online_page_free(struct page *page); +extern int try_online_node(int nid); + #ifdef CONFIG_MEMORY_HOTREMOVE extern bool is_pageblock_removable_nolock(struct page *page); extern int arch_remove_memory(u64 start, u64 size); @@ -225,6 +227,11 @@ static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) { } +static inline int try_online_node(int nid) +{ + return 0; +} + static inline void lock_memory_hotplug(void) {} static inline void unlock_memory_hotplug(void) {} @@ -256,7 +263,6 @@ static inline void remove_memory(int nid, u64 start, u64 size) {} extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, void *arg, int (*func)(struct memory_block *, void *)); -extern int mem_online_node(int nid); extern int add_memory(int nid, u64 start, u64 size); extern int arch_add_memory(int nid, u64 start, u64 size); extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); diff --git a/kernel/cpu.c b/kernel/cpu.c index d7f07a2..c10b285 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -420,11 +420,6 @@ int cpu_up(unsigned int cpu) { int err = 0; -#ifdef CONFIG_MEMORY_HOTPLUG - int nid; - pg_data_t *pgdat; -#endif - if (!cpu_possible(cpu)) { printk(KERN_ERR "can't online cpu %d because it is not " "configured as may-hotadd at boot time\n", cpu); @@ -435,27 +430,9 @@ int cpu_up(unsigned int cpu) return -EINVAL; } -#ifdef CONFIG_MEMORY_HOTPLUG - nid = cpu_to_node(cpu); - if (!node_online(nid)) { - err = mem_online_node(nid); - if (err) - return err; - } - - pgdat = NODE_DATA(nid); - if (!pgdat) { - printk(KERN_ERR - "Can't online cpu %d due to NULL pgdat\n", cpu); - return -ENOMEM; - } - - if (pgdat->node_zonelists->_zonerefs->zone == NULL) { - mutex_lock(&zonelists_mutex); - build_all_zonelists(NULL, NULL); - mutex_unlock(&zonelists_mutex); - } -#endif + err = try_online_node(cpu_to_node(cpu)); + if (err) + return err; cpu_maps_update_begin(); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index ed85fe3..c326bdf 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1044,14 +1044,19 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) } -/* +/** + * try_online_node - online a node if offlined + * * called by cpu_up() to online a node without onlined memory. */ -int mem_online_node(int nid) +int try_online_node(int nid) { pg_data_t *pgdat; int ret; + if (node_online(nid)) + return 0; + lock_memory_hotplug(); pgdat = hotadd_new_pgdat(nid, 0); if (!pgdat) { @@ -1062,6 +1067,12 @@ int mem_online_node(int nid) ret = register_one_node(nid); BUG_ON(ret); + if (pgdat->node_zonelists->_zonerefs->zone == NULL) { + mutex_lock(&zonelists_mutex); + build_all_zonelists(NULL, NULL); + mutex_unlock(&zonelists_mutex); + } + out: unlock_memory_hotplug(); return ret; -- 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/