From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm, page_alloc: add scheduling point to memmap_init_zone memmap_init_zone gets a pfn range to initialize 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. Link: http://lkml.kernel.org/r/20170918121410.24466-3-mhocko@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Reported-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Tested-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) diff -puN mm/page_alloc.c~mm-page_alloc-add-scheduling-point-to-memmap_init_zone mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-add-scheduling-point-to-memmap_init_zone +++ a/mm/page_alloc.c @@ -5367,6 +5367,7 @@ not_early: __init_single_page(page, pfn, zone, nid); set_pageblock_migratetype(page, MIGRATE_MOVABLE); + cond_resched(); } else { __init_single_pfn(pfn, zone, nid); } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
