From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id EFFA16B004D for ; Fri, 13 Nov 2009 05:59:54 -0500 (EST) Date: Fri, 13 Nov 2009 11:59:44 +0100 From: Andi Kleen Subject: [PATCH] Allow memory hotplug and hibernation in the same kernel Message-ID: <20091113105944.GA16028@basil.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org To: akpm@linux-foundation.org, linux-mm@kvack.org, gerald.schaefer@de.ibm.com, rjw@sisk.pl, linux-kernel@vger.kernel.org List-ID: Allow memory hotplug and hibernation in the same kernel Memory hotplug and hibernation was excluded in Kconfig. This is obviously a problem for distribution kernels who want to support both in the same image. After some discussions with Rafael and others the only problem is with parallel memory hotadd or removal while a hibernation operation is in process. It was also working for s390 before. This patch removes the Kconfig level exclusion, and simply makes the memory add / remove functions grab the pm_mutex to exclude against hibernation. This is a 2.6.32 candidate. Cc: gerald.schaefer@de.ibm.com Cc: rjw@sisk.pl Signed-off-by: Andi Kleen --- include/linux/suspend.h | 21 +++++++++++++++++++-- mm/Kconfig | 5 +---- mm/memory_hotplug.c | 21 +++++++++++++++++---- 3 files changed, 37 insertions(+), 10 deletions(-) Index: linux-2.6.32-rc6-ak/include/linux/suspend.h =================================================================== --- linux-2.6.32-rc6-ak.orig/include/linux/suspend.h +++ linux-2.6.32-rc6-ak/include/linux/suspend.h @@ -301,6 +301,8 @@ static inline int unregister_pm_notifier #define pm_notifier(fn, pri) do { (void)(fn); } while (0) #endif /* !CONFIG_PM_SLEEP */ +extern struct mutex pm_mutex; + #ifndef CONFIG_HIBERNATION static inline void register_nosave_region(unsigned long b, unsigned long e) { @@ -308,8 +310,23 @@ static inline void register_nosave_regio static inline void register_nosave_region_late(unsigned long b, unsigned long e) { } -#endif -extern struct mutex pm_mutex; +static inline void lock_hibernation(void) {} +static inline void unlock_hibernation(void) {} + +#else + +/* Let some subsystems like memory hotadd exclude hibernation */ + +static inline void lock_hibernation(void) +{ + mutex_lock(&pm_mutex); +} + +static inline void unlock_hibernation(void) +{ + mutex_unlock(&pm_mutex); +} +#endif #endif /* _LINUX_SUSPEND_H */ Index: linux-2.6.32-rc6-ak/mm/Kconfig =================================================================== --- linux-2.6.32-rc6-ak.orig/mm/Kconfig +++ linux-2.6.32-rc6-ak/mm/Kconfig @@ -128,12 +128,9 @@ config SPARSEMEM_VMEMMAP config MEMORY_HOTPLUG bool "Allow for memory hot-add" depends on SPARSEMEM || X86_64_ACPI_NUMA - depends on HOTPLUG && !(HIBERNATION && !S390) && ARCH_ENABLE_MEMORY_HOTPLUG + depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) -comment "Memory hotplug is currently incompatible with Software Suspend" - depends on SPARSEMEM && HOTPLUG && HIBERNATION && !S390 - config MEMORY_HOTPLUG_SPARSE def_bool y depends on SPARSEMEM && MEMORY_HOTPLUG Index: linux-2.6.32-rc6-ak/mm/memory_hotplug.c =================================================================== --- linux-2.6.32-rc6-ak.orig/mm/memory_hotplug.c +++ linux-2.6.32-rc6-ak/mm/memory_hotplug.c @@ -26,6 +26,7 @@ #include #include #include +#include #include @@ -484,14 +485,18 @@ int __ref add_memory(int nid, u64 start, struct resource *res; int ret; + lock_hibernation(); + res = register_memory_resource(start, size); + ret = -EEXIST; if (!res) - return -EEXIST; + goto out; if (!node_online(nid)) { pgdat = hotadd_new_pgdat(nid, start); + ret = -ENOMEM; if (!pgdat) - return -ENOMEM; + goto out; new_pgdat = 1; } @@ -514,7 +519,8 @@ int __ref add_memory(int nid, u64 start, BUG_ON(ret); } - return ret; + goto out; + error: /* rollback pgdat allocation and others */ if (new_pgdat) @@ -522,6 +528,8 @@ error: if (res) release_memory_resource(res); +out: + unlock_hibernation(); return ret; } EXPORT_SYMBOL_GPL(add_memory); @@ -758,6 +766,8 @@ int offline_pages(unsigned long start_pf if (!test_pages_in_a_zone(start_pfn, end_pfn)) return -EINVAL; + lock_hibernation(); + zone = page_zone(pfn_to_page(start_pfn)); node = zone_to_nid(zone); nr_pages = end_pfn - start_pfn; @@ -765,7 +775,7 @@ int offline_pages(unsigned long start_pf /* set above range as isolated */ ret = start_isolate_page_range(start_pfn, end_pfn); if (ret) - return ret; + goto out; arg.start_pfn = start_pfn; arg.nr_pages = nr_pages; @@ -843,6 +853,7 @@ repeat: writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); + unlock_hibernation(); return 0; failed_removal: @@ -852,6 +863,8 @@ failed_removal: /* pushback to free area */ undo_isolate_page_range(start_pfn, end_pfn); +out: + unlock_hibernation(); return ret; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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