From 9b6e63cbf85b89b2dbffa4955dbf2df8250e5375 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Tue, 3 Oct 2017 16:16:19 -0700 Subject: [PATCH] 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 NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720] [...] task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000 RIP: move_pfn_range_to_zone+0x185/0x1d0 [...] Call Trace: devm_memremap_pages+0x2c7/0x430 pmem_attach_disk+0x2fd/0x3f0 [nd_pmem] nvdimm_bus_probe+0x64/0x110 [libnvdimm] driver_probe_device+0x1f7/0x420 bus_for_each_drv+0x52/0x80 __device_attach+0xb0/0x130 bus_probe_device+0x87/0xa0 device_add+0x3fc/0x5f0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x43/0x150 process_one_work+0x14e/0x410 worker_thread+0x116/0x490 kthread+0xc7/0xe0 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@kernel.org Signed-off-by: Michal Hocko Reported-by: Johannes Thumshirn Tested-by: Johannes Thumshirn Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 38d165a87860..77e4d3c5c57b 100644 --- a/mm/page_alloc.c +++ b/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); } -- 2.20.1