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| author | Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> | 2014-10-29 21:50:40 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-29 23:33:14 (GMT) |
| commit | 35dca71c1fad13616d9ea336c05730071793b63a (patch) | |
| tree | 90e753169614b2f9bc91db8d01f1eb02e7ac6a01 | |
| parent | eaf3a659086e1d1d85dc8fbce4007e3c9076e0b3 (diff) | |
| download | linux-35dca71c1fad13616d9ea336c05730071793b63a.tar.xz | |
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>
| -rw-r--r-- | mm/memory_hotplug.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 29d8693..252e1db 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1912,7 +1912,6 @@ void try_offline_node(int 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) { @@ -1941,10 +1940,6 @@ 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; |