Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758278Ab1EBVuY (ORCPT ); Mon, 2 May 2011 17:50:24 -0400 Received: from router-fw.net-space.pl ([89.174.63.77]:46642 "EHLO router-fw.net-space.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756157Ab1EBVuT (ORCPT ); Mon, 2 May 2011 17:50:19 -0400 Date: Mon, 2 May 2011 23:49:21 +0200 From: Daniel Kiper To: ian.campbell@citrix.com, akpm@linux-foundation.org, andi.kleen@intel.com, haicheng.li@linux.intel.com, fengguang.wu@intel.com, jeremy@goop.org, konrad.wilk@oracle.com, dan.magenheimer@oracle.com, v.tolstov@selfip.ru, pasik@iki.fi, dave@linux.vnet.ibm.com, wdauchy@gmail.com, rientjes@google.com, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH V2 2/2] mm: Extend memory hotplug API to allow memory hotplug in virtual machines Message-ID: <20110502214921.GH4623@router-fw-old.local.net-space.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4936 Lines: 155 This patch contains online_page_callback and apropriate functions for registering/unregistering online page callbacks. It allows to do some machine specific tasks during online page stage which is required to implement memory hotplug in virtual machines. Additionally, __online_page_set_limits(), __online_page_increment_counters() and __online_page_free() function was added to ease generic hotplug operation. Signed-off-by: Daniel Kiper --- include/linux/memory_hotplug.h | 11 +++++- mm/memory_hotplug.c | 68 ++++++++++++++++++++++++++++++++++++++-- 2 files changed, 74 insertions(+), 5 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 8122018..014bd96 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -68,12 +68,19 @@ static inline void zone_seqlock_init(struct zone *zone) extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages); extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages); extern int add_one_highpage(struct page *page, int pfn, int bad_ppro); -/* need some defines for these for archs that don't support it */ -extern void online_page(struct page *page); /* VM interface that may be used by firmware interface */ extern int online_pages(unsigned long, unsigned long); extern void __offline_isolated_pages(unsigned long, unsigned long); +typedef void (*online_page_callback_t)(struct page *page); + +extern int register_online_page_callback(online_page_callback_t callback); +extern int unregister_online_page_callback(online_page_callback_t callback); + +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); + #ifdef CONFIG_MEMORY_HOTREMOVE extern bool is_pageblock_removable_nolock(struct page *page); #endif /* CONFIG_MEMORY_HOTREMOVE */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a807ccb..6bf78be 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -34,6 +34,17 @@ #include "internal.h" +/* + * online_page_callback contains pointer to current page onlining function. + * Initially it is generic_online_page(). If it is required it could be + * changed by calling register_online_page_callback() for callback registration + * and unregister_online_page_callback() for callback unregistration. + */ + +static void generic_online_page(struct page *page); + +static online_page_callback_t online_page_callback = generic_online_page; + DEFINE_MUTEX(mem_hotplug_mutex); void lock_memory_hotplug(void) @@ -361,23 +372,74 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, } EXPORT_SYMBOL_GPL(__remove_pages); -void online_page(struct page *page) +int register_online_page_callback(online_page_callback_t callback) +{ + int rc = -EPERM; + + lock_memory_hotplug(); + + if (online_page_callback == generic_online_page) { + online_page_callback = callback; + rc = 0; + } + + unlock_memory_hotplug(); + + return rc; +} +EXPORT_SYMBOL_GPL(register_online_page_callback); + +int unregister_online_page_callback(online_page_callback_t callback) +{ + int rc = -EPERM; + + lock_memory_hotplug(); + + if (online_page_callback == callback) { + online_page_callback = generic_online_page; + rc = 0; + } + + unlock_memory_hotplug(); + + return rc; +} +EXPORT_SYMBOL_GPL(unregister_online_page_callback); + +void __online_page_set_limits(struct page *page) { unsigned long pfn = page_to_pfn(page); - totalram_pages++; if (pfn >= num_physpages) num_physpages = pfn + 1; +} +EXPORT_SYMBOL_GPL(__online_page_set_limits); + +void __online_page_increment_counters(struct page *page) +{ + totalram_pages++; #ifdef CONFIG_HIGHMEM if (PageHighMem(page)) totalhigh_pages++; #endif +} +EXPORT_SYMBOL_GPL(__online_page_increment_counters); +void __online_page_free(struct page *page) +{ ClearPageReserved(page); init_page_count(page); __free_page(page); } +EXPORT_SYMBOL_GPL(__online_page_free); + +static void generic_online_page(struct page *page) +{ + __online_page_set_limits(page); + __online_page_increment_counters(page); + __online_page_free(page); +} static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, void *arg) @@ -388,7 +450,7 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, if (PageReserved(pfn_to_page(start_pfn))) for (i = 0; i < nr_pages; i++) { page = pfn_to_page(start_pfn + i); - online_page(page); + online_page_callback(page); onlined_pages++; } *(unsigned long *)arg = onlined_pages; -- 1.5.6.5 -- 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/