On 2012/11/1 17:44, Wen Congyang wrote: > 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 <rientjes@xxxxxxxxxx> > CC: Jiang Liu <liuj97@xxxxxxxxx> > CC: Len Brown <len.brown@xxxxxxxxx> > CC: Christoph Lameter <cl@xxxxxxxxx> > Cc: Minchan Kim <minchan.kim@xxxxxxxxx> > CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> > Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> > --- > drivers/acpi/acpi_memhotplug.c | 8 +++++- > include/linux/memory_hotplug.h | 2 +- > mm/memory_hotplug.c | 58 ++++++++++++++++++++++++++++++++++++++++-- > 3 files changed, 64 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c > index 24c807f..0780f99 100644 > --- a/drivers/acpi/acpi_memhotplug.c > +++ b/drivers/acpi/acpi_memhotplug.c > @@ -310,7 +310,9 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) > { > int result; > struct acpi_memory_info *info, *n; > + int node; > > + node = acpi_get_node(mem_device->device->handle); > > /* > * Ask the VM to offline this memory range. > @@ -318,7 +320,11 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) > */ > list_for_each_entry_safe(info, n, &mem_device->res_list, list) { > if (info->enabled) { > - result = remove_memory(info->start_addr, info->length); > + if (node < 0) > + node = memory_add_physaddr_to_nid( > + info->start_addr); > + result = remove_memory(node, info->start_addr, > + info->length); > if (result) > return result; > } > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index d4c4402..7b4cfe6 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -231,7 +231,7 @@ 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 node, 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 7bcced0..d965da3 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -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> > > @@ -1299,7 +1300,58 @@ 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; how about: if (nr_cpus_node(nid)) 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; > @@ -1346,6 +1398,8 @@ repeat: > > arch_remove_memory(start, size); > > + try_offline_node(nid); > + > unlock_memory_hotplug(); > > return 0; > @@ -1355,7 +1409,7 @@ 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; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html