| Message ID | 20230320080347.32434-1-linux@steffen.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [v5.10-rt] kernel: fork: set wake_q_sleeper.next=NULL again in dup_task_struct | expand |
On Mon, Mar 20, 2023 at 09:03:47AM +0100, linux@steffen.cc wrote: > From: Steffen Dirkwinkel <s.dirkwinkel@beckhoff.com> > > Without this we get system hangs within a couple of days. > It's also reproducible in minutes with "stress-ng --exec 20". > > Example error in dmesg: > INFO: task stress-ng:163916 blocked for more than 120 seconds. > Not tainted 5.10.168-rt83 #2 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:stress-ng state:D stack: 0 pid:163916 ppid: 72833 flags:0x00004000 > Call Trace: > __schedule+0x2bd/0x940 > preempt_schedule_lock+0x23/0x50 > rt_spin_lock_slowlock_locked+0x117/0x2c0 > rt_spin_lock_slowlock+0x51/0x80 > rt_write_lock+0x1e/0x1c0 > do_exit+0x3ac/0xb20 > do_group_exit+0x39/0xb0 > get_signal+0x145/0x960 > ? wake_up_new_task+0x21f/0x3c0 > arch_do_signal_or_restart+0xf1/0x830 > ? __x64_sys_futex+0x146/0x1d0 > exit_to_user_mode_prepare+0x116/0x1a0 > syscall_exit_to_user_mode+0x28/0x190 > entry_SYSCALL_64_after_hwframe+0x61/0xc6 > RIP: 0033:0x7f738d9074a7 > RSP: 002b:00007ffdafda3cb0 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: fffffffffffffe00 RBX: 00000000000000ca RCX: 00007f738d9074a7 > RDX: 0000000000028051 RSI: 0000000000000000 RDI: 00007f738be949d0 > RBP: 00007ffdafda3d88 R08: 0000000000000000 R09: 00007f738be94700 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000028051 > R13: 00007f738be949d0 R14: 00007ffdafda51e0 R15: 00007f738be94700 > > Fixes: 1ba44dcf789d ("Merge tag 'v5.10.162' into v5.10-rt") Thank you for spotting and investigating that! I dropped that specific line while fixing a small merge conflict from 788d0824269b io_uring: import 5.15-stable io_uring Interestingly enough, I didn't see that problem while running stress-ng. I may need to add a few more, different, systems to my test base. Anyway, I will add this fix to the next build. Luis > Signed-off-by: Steffen Dirkwinkel <s.dirkwinkel@beckhoff.com> > --- > kernel/fork.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/fork.c b/kernel/fork.c > index c6e0d555fca9..0c4c20eb762c 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -949,6 +949,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) > tsk->splice_pipe = NULL; > tsk->task_frag.page = NULL; > tsk->wake_q.next = NULL; > + tsk->wake_q_sleeper.next = NULL; > tsk->pf_io_worker = NULL; > > account_kernel_stack(tsk, 1); > -- > 2.40.0 > ---end quoted text---
I have just checked the 5.15-rt branch on stable-rt and it is also missing this line.
Sorry - just ignore - I now see that 5.15 didn't need this change.
diff --git a/kernel/fork.c b/kernel/fork.c index c6e0d555fca9..0c4c20eb762c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -949,6 +949,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) tsk->splice_pipe = NULL; tsk->task_frag.page = NULL; tsk->wake_q.next = NULL; + tsk->wake_q_sleeper.next = NULL; tsk->pf_io_worker = NULL; account_kernel_stack(tsk, 1);