From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tang Chen Date: Wed, 09 Jan 2013 09:32:38 +0000 Subject: [PATCH v6 14/15] memory-hotplug: free node_data when a node is offlined Message-Id: <1357723959-5416-15-git-send-email-tangchen@cn.fujitsu.com> List-Id: References: <1357723959-5416-1-git-send-email-tangchen@cn.fujitsu.com> In-Reply-To: <1357723959-5416-1-git-send-email-tangchen@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org, rientjes@google.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, wujianguo@huawei.com, wency@cn.fujitsu.com, tangchen@cn.fujitsu.com, hpa@zytor.com, linfeng@cn.fujitsu.com, laijs@cn.fujitsu.com, mgorman@suse.de, yinghai@kernel.org, glommer@parallels.com Cc: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org From: Wen Congyang 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 Reviewed-by: Kamezawa Hiroyuki --- 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