From: Michal Hocko <mhocko@xxxxxxxx>
memmap_init_zone gets a pfn range to intialize and it can be really
large resulting in a soft lockup on non-preemptible kernels
[ 65.585596] NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720]
[...]
[ 65.585818] task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000
[ 65.585819] RIP: 0010:[<ffffffff815ff545>] [<ffffffff815ff545>] move_pfn_range_to_zone+0x185/0x1d0
[...]
[ 65.585843] Call Trace:
[ 65.585853] [<ffffffff8118b657>] devm_memremap_pages+0x2c7/0x430
[ 65.585862] [<ffffffffa02d650d>] pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
[ 65.585893] [<ffffffffa14bb984>] nvdimm_bus_probe+0x64/0x110 [libnvdimm]
[ 65.585904] [<ffffffff8146b257>] driver_probe_device+0x1f7/0x420
[ 65.585910] [<ffffffff81469212>] bus_for_each_drv+0x52/0x80
[ 65.585913] [<ffffffff8146af40>] __device_attach+0xb0/0x130
[ 65.585916] [<ffffffff8146a367>] bus_probe_device+0x87/0xa0
[ 65.585919] [<ffffffff814682fc>] device_add+0x3fc/0x5f0
[ 65.585924] [<ffffffffa14baffe>] nd_async_device_register+0xe/0x40 [libnvdimm]
[ 65.585927] [<ffffffff8109e413>] async_run_entry_fn+0x43/0x150
[ 65.585933] [<ffffffff81095b8e>] process_one_work+0x14e/0x410
[ 65.585937] [<ffffffff810963f6>] worker_thread+0x116/0x490
[ 65.585939] [<ffffffff8109b8c7>] kthread+0xc7/0xe0
[ 65.585943] [<ffffffff8160a57f>] ret_from_fork+0x3f/0x70
Fix this by adding a scheduling point once per page block.
Reported-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
mm/page_alloc.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fc36755a21cf..41e93dfc702e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5320,6 +5320,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
__init_single_page(page, pfn, zone, nid);
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ cond_resched();
} else {
__init_single_pfn(pfn, zone, nid);
}
--
2.14.1
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