Commit 35dca71c1fad13616d9ea336c05730071793b63a
Committed by
Linus Torvalds
1 parent
eaf3a65908
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
memory-hotplug: clear pgdat which is allocated by bootmem in try_offline_node()
When hot adding the same memory after hot removal, the following messages are shown: WARNING: CPU: 20 PID: 6 at mm/page_alloc.c:4968 free_area_init_node+0x3fe/0x426() ... Call Trace: dump_stack+0x46/0x58 warn_slowpath_common+0x81/0xa0 warn_slowpath_null+0x1a/0x20 free_area_init_node+0x3fe/0x426 hotadd_new_pgdat+0x90/0x110 add_memory+0xd4/0x200 acpi_memory_device_add+0x1aa/0x289 acpi_bus_attach+0xfd/0x204 acpi_bus_attach+0x178/0x204 acpi_bus_scan+0x6a/0x90 acpi_device_hotplug+0xe8/0x418 acpi_hotplug_work_fn+0x1f/0x2b process_one_work+0x14e/0x3f0 worker_thread+0x11b/0x510 kthread+0xe1/0x100 ret_from_fork+0x7c/0xb0 The detaled explanation is as follows: When hot removing memory, pgdat is set to 0 in try_offline_node(). But if the pgdat is allocated by bootmem allocator, the clearing step is skipped. And when hot adding the same memory, the uninitialized pgdat is reused. But free_area_init_node() checks wether pgdat is set to zero. As a result, free_area_init_node() hits WARN_ON(). This patch clears pgdat which is allocated by bootmem allocator in try_offline_node(). Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 0 additions and 5 deletions Side-by-side Diff
mm/memory_hotplug.c
... | ... | @@ -1912,7 +1912,6 @@ |
1912 | 1912 | unsigned long start_pfn = pgdat->node_start_pfn; |
1913 | 1913 | unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; |
1914 | 1914 | unsigned long pfn; |
1915 | - struct page *pgdat_page = virt_to_page(pgdat); | |
1916 | 1915 | int i; |
1917 | 1916 | |
1918 | 1917 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
... | ... | @@ -1940,10 +1939,6 @@ |
1940 | 1939 | */ |
1941 | 1940 | node_set_offline(nid); |
1942 | 1941 | unregister_one_node(nid); |
1943 | - | |
1944 | - if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page)) | |
1945 | - /* node data is allocated from boot memory */ | |
1946 | - return; | |
1947 | 1942 | |
1948 | 1943 | /* free waittable in each zone */ |
1949 | 1944 | for (i = 0; i < MAX_NR_ZONES; i++) { |