[DragonFlyBSD - Bug #2137] (Closed) vm_prefault: Warning, backing object race averted lobject

bugtracker-admin at leaf.dragonflybsd.org bugtracker-admin at leaf.dragonflybsd.org
Sat Oct 23 14:24:43 PDT 2021

Issue #2137 has been updated by y0n3t4n1.

Description updated
Status changed from New to Closed
Assignee deleted (0)

Closing this as I doubt I can reproduce it with the current kernel.

Bug #2137: vm_prefault: Warning, backing object race averted lobject

* Author: y0n3t4n1
* Status: Closed
* Priority: Normal
* Target version: 6.2
As I wrote in issue2118, after the fix (1f8fc82a) I started seeing
warning messages on the console under load:

  vm_prefault: Warning, backing object race averted lobject 0xffffffe0749d3210

The system used to panic(backtrace at the end of this message) within
a day or two, but with the kernel built from more recent source(fa7cb8ce),
it no longer panics (well, at least for 4 days) running the same load
(pkgsrc bulk build with MAKE_JOBS=5 defined), just the warning messages
shown above all over the console.

    #4  0xffffffff8039c50f in panic (
	fmt=0xffffffff805edf90 "Bad link elm %p prev->next != elm")
	at /usr/src/sys/kern/kern_shutdown.c:833
    #5  0xffffffff80532b35 in vm_object_deallocate_locked (
	object=0xffffffe0690b2d10) at /usr/src/sys/vm/vm_object.c:601
    #6  0xffffffff80532c0f in vm_object_deallocate (object=0xffffffe06b9eed10)
	at /usr/src/sys/vm/vm_object.c:451
    #7  0xffffffff8052d5bd in vm_map_entry_delete (countp=<optimized out>,
	entry=<optimized out>, map=<optimized out>)
	at /usr/src/sys/vm/vm_map.c:2608
    #8  vm_map_delete (map=0xffffffe05b0d9a00, start=<optimized out>,
	end=140737488355328, countp=<optimized out>)
	at /usr/src/sys/vm/vm_map.c:2753
    #9  0xffffffff8052d661 in vm_map_remove (map=0xffffffe05b0d9a00, start=0,
	end=<unavailable>) at /usr/src/sys/vm/vm_map.c:2774
    #10 0xffffffff8052d6e9 in vmspace_terminate (vm=0xffffffe05b0d9a00)
	at /usr/src/sys/vm/vm_map.c:310
    #11 0xffffffff80370579 in _sysref_put (sr=0xffffffe05b0d9bd0)
	at /usr/src/sys/kern/kern_sysref.c:325
    #12 0xffffffff80388079 in sysref_put (sr=<optimized out>)
	at /usr/src/sys/sys/sysref2.h:83
    #13 exit1 (rv=<optimized out>) at /usr/src/sys/kern/kern_exit.c:417
    #14 0xffffffff803884a4 in sys_exit (uap=<optimized out>)
	at /usr/src/sys/kern/kern_exit.c:121
    #15 0xffffffff805b0308 in syscall2 (frame=0xffffffe076d33c08)
	at /usr/src/sys/platform/pc64/x86_64/trap.c:1188
    #16 0xffffffff805a88df in Xfast_syscall ()
	at /usr/src/sys/platform/pc64/x86_64/exception.S:320
    #17 0x000000000000002b in ?? ()

Best Regards,

You have received this notification because you have either subscribed to it, or are involved in it.
To change your notification preferences, please click here: http://bugs.dragonflybsd.org/my/account

More information about the Bugs mailing list