This is a note to let you know that I've just added the patch titled
mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-page_alloc-fix-watchdog-soft-lockups-during-set_zone_contiguous.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e84fe99b68ce353c37ceeecc95dce9696c976556 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@xxxxxxxxxx>
Date: Thu, 7 May 2020 18:35:46 -0700
Subject: mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()
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
@@ -1555,6 +1555,7 @@ 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 */
Patches currently in stable-queue which might be from david@xxxxxxxxxx are
queue-5.4/mm-page_alloc-fix-watchdog-soft-lockups-during-set_zone_contiguous.patch
queue-5.4/mm-limit-boost_watermark-on-small-zones.patch
queue-5.4/kvm-s390-remove-false-warn_on_once-for-the-pqap-instruction.patch
