Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754209Ab3IJDfG (ORCPT ); Mon, 9 Sep 2013 23:35:06 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:53336 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407Ab3IJDfD (ORCPT ); Mon, 9 Sep 2013 23:35:03 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.0.1 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20120718-3 Message-ID: <522E9351.6000107@jp.fujitsu.com> Date: Tue, 10 Sep 2013 12:34:41 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Toshi Kani CC: , , , , , Subject: Re: [PATCH] cpu/mem hotplug: Add try_online_node() for cpu_up() References: <1378772671-27280-1-git-send-email-toshi.kani@hp.com> <522E92A0.80502@jp.fujitsu.com> In-Reply-To: <522E92A0.80502@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-SecurityPolicyCheck-GC: OK by FENCE-Mail Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5608 Lines: 177 (2013/09/10 12:31), Yasuaki Ishimatsu wrote: > (2013/09/10 9:24), Toshi Kani wrote: >> 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); > > Please move this comments into try_online_node() too. In this case, please use pr_err() instead of printk(). Thanks, Yasuaki Ishimatsu > > Thanks, > Yasuaki Ishimatsu > >> - 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, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: email@kvack.org >> > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org > -- 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/