[PATCH 10/10] memory-hotplug : remove sysfs file of node
From: Wen Congyang This patch introduces 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. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Yasuaki Ishimatsu Signed-off-by: Wen Congyang --- mm/memory_hotplug.c | 54 1 file changed, 54 insertions(+) Index: linux-3.6/mm/memory_hotplug.c === --- linux-3.6.orig/mm/memory_hotplug.c 2012-10-04 18:30:31.767709165 +0900 +++ linux-3.6/mm/memory_hotplug.c 2012-10-04 18:32:46.907842637 +0900 @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -1276,6 +1277,57 @@ int offline_memory(u64 start, u64 size) return 0; } +static int check_cpu_on_node(void *data) +{ + struct pglist_data *pgdat = data; + int cpu; + + for_each_online_cpu(cpu) { + if (cpu_to_node(cpu) == pgdat->node_id) + /* +* the cpu on this node is onlined, 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 sections 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) { int ret = 0; @@ -1296,6 +1348,8 @@ int __ref remove_memory(int nid, u64 sta firmware_map_remove(start, start + size, "System RAM"); arch_remove_memory(start, size); + + try_offline_node(nid); out: unlock_memory_hotplug(); return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 10/10] memory-hotplug : remove sysfs file of node
From: Wen Congyang we...@cn.fujitsu.com This patch introduces 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. CC: David Rientjes rient...@google.com CC: Jiang Liu liu...@gmail.com CC: Len Brown len.br...@intel.com CC: Christoph Lameter c...@linux.com Cc: Minchan Kim minchan@gmail.com CC: Andrew Morton a...@linux-foundation.org CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com CC: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com Signed-off-by: Wen Congyang we...@cn.fujitsu.com --- mm/memory_hotplug.c | 54 1 file changed, 54 insertions(+) Index: linux-3.6/mm/memory_hotplug.c === --- linux-3.6.orig/mm/memory_hotplug.c 2012-10-04 18:30:31.767709165 +0900 +++ linux-3.6/mm/memory_hotplug.c 2012-10-04 18:32:46.907842637 +0900 @@ -29,6 +29,7 @@ #include linux/suspend.h #include linux/mm_inline.h #include linux/firmware-map.h +#include linux/stop_machine.h #include asm/tlbflush.h @@ -1276,6 +1277,57 @@ int offline_memory(u64 start, u64 size) return 0; } +static int check_cpu_on_node(void *data) +{ + struct pglist_data *pgdat = data; + int cpu; + + for_each_online_cpu(cpu) { + if (cpu_to_node(cpu) == pgdat-node_id) + /* +* the cpu on this node is onlined, 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 sections 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) { int ret = 0; @@ -1296,6 +1348,8 @@ int __ref remove_memory(int nid, u64 sta firmware_map_remove(start, start + size, System RAM); arch_remove_memory(start, size); + + try_offline_node(nid); out: unlock_memory_hotplug(); return ret; -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/