From: David Hildenbrand <david@xxxxxxxxxx> commit e84fe99b68ce353c37ceeecc95dce9696c976556 upstream. Without CONFIG_PREEMPT, it can happen that we get soft lockups detected, e.g., while booting up. watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-next-20200331+ #4 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 RIP: __pageblock_pfn_to_page+0x134/0x1c0 Call Trace: set_zone_contiguous+0x56/0x70 page_alloc_init_late+0x166/0x176 kernel_init_freeable+0xfa/0x255 kernel_init+0xa/0x106 ret_from_fork+0x35/0x40 The issue becomes visible when having a lot of memory (e.g., 4TB) assigned to a single NUMA node - a system that can easily be created using QEMU. Inside VMs on a hypervisor with quite some memory overcommit, this is fairly easy to trigger. Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Reviewed-by: Baoquan He <bhe@xxxxxxxxxx> Reviewed-by: Shile Zhang <shile.zhang@xxxxxxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> Cc: Shile Zhang <shile.zhang@xxxxxxxxxxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Alexander Duyck <alexander.duyck@xxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20200416073417.5003-1-david@xxxxxxxxxx Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1405,6 +1405,7 @@ void set_zone_contiguous(struct zone *zo if (!__pageblock_pfn_to_page(block_start_pfn, block_end_pfn, zone)) return; + cond_resched(); } /* We confirm that there is no hole */
