[PATCH v6 14/15] memory-hotplug: free node_data when a node is offlined
From: Tang Chen <hidden>
Date: 2013-01-09 09:34:03
Also in:
linux-acpi, linux-mm, linux-s390, linux-sh, linuxppc-dev, lkml
Subsystem:
memory hot(un)plug, memory management, the rest · Maintainers:
David Hildenbrand, Oscar Salvador, Andrew Morton, Linus Torvalds
From: Wen Congyang <redacted> We call hotadd_new_pgdat() to allocate memory to store node_data. So we should free it when removing a node. Signed-off-by: Wen Congyang <redacted> Reviewed-by: Kamezawa Hiroyuki <redacted> --- mm/memory_hotplug.c | 30 +++++++++++++++++++++++++++--- 1 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a8703f7..8b67752 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c@@ -1699,9 +1699,12 @@ static int check_cpu_on_node(void *data) /* 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; + pg_data_t *pgdat = NODE_DATA(nid); + unsigned long start_pfn = pgdat->node_start_pfn; + unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; unsigned long pfn; + struct page *pgdat_page = virt_to_page(pgdat); + int i; for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { unsigned long section_nr = pfn_to_section_nr(pfn);
@@ -1719,7 +1722,7 @@ static void try_offline_node(int nid) return; } - if (stop_machine(check_cpu_on_node, NODE_DATA(nid), NULL)) + if (stop_machine(check_cpu_on_node, pgdat, NULL)) return; /*
@@ -1728,6 +1731,27 @@ static void try_offline_node(int nid) */ node_set_offline(nid); unregister_one_node(nid); + + if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page)) + /* node data is allocated from boot memory */ + return; + + /* free waittable in each zone */ + for (i = 0; i < MAX_NR_ZONES; i++) { + struct zone *zone = pgdat->node_zones + i; + + if (zone->wait_table) + vfree(zone->wait_table); + } + + /* + * Since there is no way to guarentee the address of pgdat/zone is not + * on stack of any kernel threads or used by other kernel objects + * without reference counting or other symchronizing method, do not + * reset node_data and free pgdat here. Just reset it to 0 and reuse + * the memory when the node is online again. + */ + memset(pgdat, 0, sizeof(*pgdat)); } int __ref remove_memory(int nid, u64 start, u64 size)
--
1.7.1