From 60a5a19e7419ba0bc22ed01b3285e8940b42944c Mon Sep 17 00:00:00 2001 From: Tang Chen Date: Fri, 22 Feb 2013 16:33:14 -0800 Subject: [PATCH] memory-hotplug: remove sysfs file of node Introduce a new function try_offline_node() to remove sysfs file of node when all memory sections of this node are removed. If some memory sections of this node are not removed, this function does nothing. Signed-off-by: Wen Congyang Signed-off-by: Tang Chen Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Wu Jianguo Cc: Yasuaki Ishimatsu Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/acpi/acpi_memhotplug.c | 8 +++-- include/linux/memory_hotplug.h | 2 +- mm/memory_hotplug.c | 58 ++++++++++++++++++++++++++++++++-- 3 files changed, 63 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 034d3e72aa92..da1f82b445e0 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -280,9 +280,11 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) { - int result = 0; + int result = 0, nid; struct acpi_memory_info *info, *n; + nid = acpi_get_node(mem_device->device->handle); + list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (info->failed) /* The kernel does not use this memory block */ @@ -295,7 +297,9 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) */ return -EBUSY; - result = remove_memory(info->start_addr, info->length); + if (nid < 0) + nid = memory_add_physaddr_to_nid(info->start_addr); + result = remove_memory(nid, info->start_addr, info->length); if (result) return result; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 4d523fe75ba1..69903ccf549e 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -248,7 +248,7 @@ extern int arch_add_memory(int nid, u64 start, u64 size); extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); extern int offline_memory_block(struct memory_block *mem); extern bool is_memblock_offlined(struct memory_block *mem); -extern int remove_memory(u64 start, u64 size); +extern int remove_memory(int nid, u64 start, u64 size); extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, int nr_pages); extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 3f792375f326..aea6374f435a 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -1679,7 +1680,58 @@ static int is_memblock_offlined_cb(struct memory_block *mem, void *arg) return ret; } -int __ref remove_memory(u64 start, u64 size) +static int check_cpu_on_node(void *data) +{ + struct pglist_data *pgdat = data; + int cpu; + + for_each_present_cpu(cpu) { + if (cpu_to_node(cpu) == pgdat->node_id) + /* + * the cpu on this node isn't removed, and we can't + * offline this node. + */ + return -EBUSY; + } + + return 0; +} + +/* offline the node if all memory sections of this node are removed */ +static void try_offline_node(int nid) +{ + unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn; + unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages; + unsigned long pfn; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (!present_section_nr(section_nr)) + continue; + + if (pfn_to_nid(pfn) != nid) + continue; + + /* + * some memory sections of this node are not removed, and we + * can't offline node now. + */ + return; + } + + if (stop_machine(check_cpu_on_node, NODE_DATA(nid), NULL)) + return; + + /* + * all memory/cpu of this node are removed, we can offline this + * node now. + */ + node_set_offline(nid); + unregister_one_node(nid); +} + +int __ref remove_memory(int nid, u64 start, u64 size) { unsigned long start_pfn, end_pfn; int ret = 0; @@ -1734,6 +1786,8 @@ int __ref remove_memory(u64 start, u64 size) arch_remove_memory(start, size); + try_offline_node(nid); + unlock_memory_hotplug(); return 0; @@ -1743,7 +1797,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) { return -EINVAL; } -int remove_memory(u64 start, u64 size) +int remove_memory(int nid, u64 start, u64 size) { return -EINVAL; }