From: David Hildenbrand david@redhat.com
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@redhat.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Reviewed-by: Pavel Tatashin pasha.tatashin@soleen.com Reviewed-by: Pankaj Gupta pankaj.gupta.linux@gmail.com Reviewed-by: Baoquan He bhe@redhat.com Reviewed-by: Shile Zhang shile.zhang@linux.alibaba.com Acked-by: Michal Hocko mhocko@suse.com Cc: Kirill Tkhai ktkhai@virtuozzo.com Cc: Shile Zhang shile.zhang@linux.alibaba.com Cc: Pavel Tatashin pasha.tatashin@soleen.com Cc: Daniel Jordan daniel.m.jordan@oracle.com Cc: Michal Hocko mhocko@kernel.org Cc: Alexander Duyck alexander.duyck@gmail.com Cc: Baoquan He bhe@redhat.com Cc: Oscar Salvador osalvador@suse.de Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20200416073417.5003-1-david@redhat.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+)
--- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1422,6 +1422,7 @@ 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 */