From c73602ad31cdcf7e6651f43d12f65b5b9b825b6f Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 7 Oct 2009 16:32:22 -0700 Subject: ksm: more on default values Adjust the max_kernel_pages default to a quarter of totalram_pages, instead of nr_free_buffer_pages() / 4: the KSM pages themselves come from highmem, and even on a 16GB PAE machine, 4GB of KSM pages would only be pinning 32MB of lowmem with their rmap_items, so no need for the more obscure calculation (nor for its own special init function). There is no way for the user to switch KSM on if CONFIG_SYSFS is not enabled, so in that case default run to KSM_RUN_MERGE. Update KSM Documentation and Kconfig to reflect the new defaults. Signed-off-by: Hugh Dickins Cc: Izik Eidus Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index edd300aca173..57963c6063d1 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -224,7 +224,9 @@ config KSM the many instances by a single resident page with that content, so saving memory until one or another app needs to modify the content. Recommended for use with KVM, or with other duplicative applications. - See Documentation/vm/ksm.txt for more information. + See Documentation/vm/ksm.txt for more information: KSM is inactive + until a program has madvised that an area is MADV_MERGEABLE, and + root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set). config DEFAULT_MMAP_MIN_ADDR int "Low address space to protect from user allocation" -- cgit v1.2.3 From ed84a07a124bf3b1aab2fd7fdb6e9534838087ac Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Fri, 16 Oct 2009 07:21:36 +0000 Subject: powerpc: Limit memory hotplug support to PPC64 Book-3S machines Signed-off-by: Kumar Gala Signed-off-by: Benjamin Herrenschmidt --- mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index 57963c6063d1..7ca3777bdede 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -129,7 +129,7 @@ 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 (IA64 || X86 || PPC64 || SUPERH || S390) + depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) comment "Memory hotplug is currently incompatible with Software Suspend" depends on SPARSEMEM && HOTPLUG && HIBERNATION && !S390 -- cgit v1.2.3 From 1a83e175dc2c7be931a3ea9c7fb0769e6de55e90 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Oct 2009 16:50:12 -0700 Subject: mm: fix sparsemem configuration Currently, sparsemem is only available if EXPERIMENTAL is enabled. However, it hasn't ever been marked experimental. It's been about four years since sparsemem was merged, and we have platforms which depend on it; allow architectures to decide whether sparsemem should be the default memory model. Signed-off-by: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index 57963c6063d1..f791196cee8c 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -67,7 +67,7 @@ config DISCONTIGMEM config SPARSEMEM def_bool y - depends on SPARSEMEM_MANUAL + depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL config FLATMEM def_bool y -- cgit v1.2.3 From 6ad696d2cf535772dff659298ec7e7260e344595 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 17 Nov 2009 14:06:22 -0800 Subject: mm: allow memory hotplug and hibernation in the same kernel Allow memory hotplug and hibernation in the same kernel Memory hotplug and hibernation were exclusive 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. Fixes a regression - old kernels didn't exclude memory hotadd and hibernation. Signed-off-by: Andi Kleen Cc: Gerald Schaefer Cc: KOSAKI Motohiro Cc: Yasunori Goto Acked-by: Rafael J. Wysocki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/suspend.h | 21 +++++++++++++++++++-- mm/Kconfig | 5 +---- mm/memory_hotplug.c | 21 +++++++++++++++++---- 3 files changed, 37 insertions(+), 10 deletions(-) (limited to 'mm/Kconfig') diff --git a/include/linux/suspend.h b/include/linux/suspend.h index cd15df6c63cd..5e781d824e6d 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -301,6 +301,8 @@ static inline int unregister_pm_notifier(struct notifier_block *nb) #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_region(unsigned long b, unsigned long e) static inline void register_nosave_region_late(unsigned long b, unsigned long e) { } -#endif -extern struct mutex pm_mutex; +static inline void lock_system_sleep(void) {} +static inline void unlock_system_sleep(void) {} + +#else + +/* Let some subsystems like memory hotadd exclude hibernation */ + +static inline void lock_system_sleep(void) +{ + mutex_lock(&pm_mutex); +} + +static inline void unlock_system_sleep(void) +{ + mutex_unlock(&pm_mutex); +} +#endif #endif /* _LINUX_SUSPEND_H */ diff --git a/mm/Kconfig b/mm/Kconfig index fd3386242cf0..44cf6f0a3a6d 100644 --- a/mm/Kconfig +++ b/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 diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 380aef45c2cf..2047465cd27c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -26,6 +26,7 @@ #include #include #include +#include #include @@ -485,14 +486,18 @@ int __ref add_memory(int nid, u64 start, u64 size) struct resource *res; int ret; + lock_system_sleep(); + 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; } @@ -515,7 +520,8 @@ int __ref add_memory(int nid, u64 start, u64 size) BUG_ON(ret); } - return ret; + goto out; + error: /* rollback pgdat allocation and others */ if (new_pgdat) @@ -523,6 +529,8 @@ error: if (res) release_memory_resource(res); +out: + unlock_system_sleep(); return ret; } EXPORT_SYMBOL_GPL(add_memory); @@ -759,6 +767,8 @@ int offline_pages(unsigned long start_pfn, if (!test_pages_in_a_zone(start_pfn, end_pfn)) return -EINVAL; + lock_system_sleep(); + zone = page_zone(pfn_to_page(start_pfn)); node = zone_to_nid(zone); nr_pages = end_pfn - start_pfn; @@ -766,7 +776,7 @@ int offline_pages(unsigned long start_pfn, /* 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; @@ -844,6 +854,7 @@ repeat: writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); + unlock_system_sleep(); return 0; failed_removal: @@ -853,6 +864,8 @@ failed_removal: /* pushback to free area */ undo_isolate_page_range(start_pfn, end_pfn); +out: + unlock_system_sleep(); return ret; } -- cgit v1.2.3