[Bug 207873] New: BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[Bug 207873] New: BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

            Bug ID: 207873
           Summary: BUG at swapops + rcu stall + soft lockup at running
                    btrfs test suite (TEST=013\* ./misc-tests.sh)
           Product: Platform Specific/Hardware
           Version: 2.5
    Kernel Version: 5.7-rc6
          Hardware: PPC-32
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: PPC-32
          Assignee: platform_ppc-32@kernel-bugs.osdl.org
          Reporter: erhard_f@mailbox.org
                CC: fs_btrfs@kernel-bugs.osdl.org
        Regression: No

Created attachment 289253
  --> https://bugzilla.kernel.org/attachment.cgi?id=289253&action=edit
kernel .config (5.7-rc6, PowerMac G4 DP)

The bug is triggered by running "TEST=013\* ./misc-tests.sh" of btrfs-progs
test suite, built from git master:

 # git clone https://github.com/kdave/btrfs-progs && cd btrfs-progs/
 # ./autogen.sh && ./configure --disable-documentation
 # make && make fssum
 # cd tests/
 # TEST=013\* ./misc-tests.sh

The G4 crashes and the reboot timer kicks in. Before it shows a series of stack
traces, starting with the "kernel BUG at include/linux/swapops.h:197!"-part
from bug #207221. After that I get an rcu stall and a soft lockup. For the full
stacktrace have a look at the transcript of both screenshots.

[...]
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: o1-....: (7799 ticks this GP) idle=a06/1/0x40000002 soft irq=11075/11075
fqs=2599
o(t=7804 jiffies g=21629 q=59)
Task dump for CPU 1:
dd              R  running task        0  2200    394 0x0000000c
Call Trace:
[f49fb458] [c00fcddc] sched_show_task+0x3bc/Ox3fe (unreliable)
[f49fb498] [c01c650c] rcu_dump_cpu_stacks+0x228/0x23c
[f49fb4e8] [c01c2e18] rcu_sched_clock_irq+0x81c/0x1360
[f49fb568] [c01d8940] update_process_times+0x2c/0x98
[f49fb588] [c02027d4] tick_sched_timer+0x128/0x1d8
[f49fb5a8] [c01dc49c] __hrtimer_run_queues+0x490/Oxae8
[f49fb698] [c01dd788] hrtimer_interrupt+0x278/0x520
[f49fb6f8] [c001710c] timer_interrupt+0x374/0xb4c
[f49fb738] [c002c5e4] ret_from_except+0x0/0x14
--- interrupt: 901 at do_raw_spin_lock+0x1c8/0x2cc
    LR = do_raw_spin_lock+0x1a4/0x2cc
[f49fb800] [c0180e0c] do_raw_spin_lock+0x188/0x2cc (unrelable)
[f49fb830] [c0428890] unmap_page_range+0x244/0xb08
[f49fb910] [c0429610] unmap_vmas+0x94/0xdc
[f49fb930] [c043c25c] exit_mmap+0x340/0x46c
[f49fba20] [c0078260] __mmput+0x78/0x360
[f49fba50] [c0090514] do_exit+0x9c4/0x21fc
[f49fbb20] [c0019d38] user_single_step_report+0x0/0x74
[f49fbb70] [c002c5e0] ret_from_except+0x0/0x4
--- interrupt: 700 at __migration_entry_wait+0x13c/0x198
    LR = __migration_entry_wait+0xf0/0x198
[f49fbc58] [c042c0f0] do_swap_page+0x1f0/0x198
[f49fbd28] [c042e7e4] handle_mm_fault+0x794/0x16f4
[f49fbe48] [c0039868] do_page_fault+0xf50/0x12f8
[f49fbf38] [c002c468] handle_page_fault+0x10/0x3c
--- interrupt: 301 at 0x87e378
    LR = 0x87e33c
[...]

I don't know wether this is a btrfs bug, or a bug only triggered by this
specific test. So I am filing this as platform specific as I have not seen it
on x86 yet.

Unlike bug #207221 KASAN is enabled here, so the stack trace looks slightly
different.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

--- Comment #1 from Erhard F. (erhard_f@mailbox.org) ---
Created attachment 289255
  --> https://bugzilla.kernel.org/attachment.cgi?id=289255&action=edit
kernel dmesg (5.7-rc6, PowerMac G4 DP)

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

--- Comment #2 from Erhard F. (erhard_f@mailbox.org) ---
Created attachment 289257
  --> https://bugzilla.kernel.org/attachment.cgi?id=289257&action=edit
screenshot 01

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

--- Comment #3 from Erhard F. (erhard_f@mailbox.org) ---
Created attachment 289259
  --> https://bugzilla.kernel.org/attachment.cgi?id=289259&action=edit
screenshot 02

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

--- Comment #4 from Erhard F. (erhard_f@mailbox.org) ---
Created attachment 289261
  --> https://bugzilla.kernel.org/attachment.cgi?id=289261&action=edit
transcript of both screenshots

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

Christophe Leroy (christophe.leroy@c-s.fr) changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |christophe.leroy@c-s.fr

--- Comment #5 from Christophe Leroy (christophe.leroy@c-s.fr) ---
Try
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=40bb0e904212cf7d6f041a98c58c8341b2016670

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 207873] BUG at swapops + rcu stall + soft lockup at running btrfs test suite (TEST=013\* ./misc-tests.sh)

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207873

Erhard F. (erhard_f@mailbox.org) changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |PATCH_ALREADY_AVAILABLE

--- Comment #6 from Erhard F. (erhard_f@mailbox.org) ---
(In reply to Christophe Leroy from comment #5)
> Try
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/
> ?id=40bb0e904212cf7d6f041a98c58c8341b2016670
Thanks for the hint! That patch did the trick. The btrfs test suite completes
fine now and building larger projects works unremarkably. 

Will close here as the fix seems to be going into -rc7.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.