On 3/1/21 6:11 PM, Jens Axboe wrote:
> On 3/1/21 5:57 PM, Alex Xu (Hello71) wrote:
>> Hi,
>>
>> On Linux 5.12-rc1, I am unable to suspend to RAM. The system freezes for
>> about 40 seconds and then continues operation. The following messages
>> are printed to the kernel log:
>>
>> [ 240.650300] PM: suspend entry (deep)
>> [ 240.650748] Filesystems sync: 0.000 seconds
>> [ 240.725605] Freezing user space processes ...
>> [ 260.739483] Freezing of tasks failed after 20.013 seconds (3 tasks refusing to freeze, wq_busy=0):
>> [ 260.739497] task:iou-mgr-446 state:S stack: 0 pid: 516 ppid: 439 flags:0x00004224
>> [ 260.739504] Call Trace:
>> [ 260.739507] ? sysvec_apic_timer_interrupt+0xb/0x81
>> [ 260.739515] ? pick_next_task_fair+0x197/0x1cde
>> [ 260.739519] ? sysvec_reschedule_ipi+0x2f/0x6a
>> [ 260.739522] ? asm_sysvec_reschedule_ipi+0x12/0x20
>> [ 260.739525] ? __schedule+0x57/0x6d6
>> [ 260.739529] ? del_timer_sync+0xb9/0x115
>> [ 260.739533] ? schedule+0x63/0xd5
>> [ 260.739536] ? schedule_timeout+0x219/0x356
>> [ 260.739540] ? __next_timer_interrupt+0xf1/0xf1
>> [ 260.739544] ? io_wq_manager+0x73/0xb1
>> [ 260.739549] ? io_wq_create+0x262/0x262
>> [ 260.739553] ? ret_from_fork+0x22/0x30
>> [ 260.739557] task:iou-mgr-517 state:S stack: 0 pid: 522 ppid: 439 flags:0x00004224
>> [ 260.739561] Call Trace:
>> [ 260.739563] ? sysvec_apic_timer_interrupt+0xb/0x81
>> [ 260.739566] ? pick_next_task_fair+0x16f/0x1cde
>> [ 260.739569] ? sysvec_apic_timer_interrupt+0xb/0x81
>> [ 260.739571] ? asm_sysvec_apic_timer_interrupt+0x12/0x20
>> [ 260.739574] ? __schedule+0x5b7/0x6d6
>> [ 260.739578] ? del_timer_sync+0x70/0x115
>> [ 260.739581] ? schedule_timeout+0x211/0x356
>> [ 260.739585] ? __next_timer_interrupt+0xf1/0xf1
>> [ 260.739588] ? io_wq_check_workers+0x15/0x11f
>> [ 260.739592] ? io_wq_manager+0x69/0xb1
>> [ 260.739596] ? io_wq_create+0x262/0x262
>> [ 260.739600] ? ret_from_fork+0x22/0x30
>> [ 260.739603] task:iou-wrk-517 state:S stack: 0 pid: 523 ppid: 439 flags:0x00004224
>> [ 260.739607] Call Trace:
>> [ 260.739609] ? __schedule+0x5b7/0x6d6
>> [ 260.739614] ? schedule+0x63/0xd5
>> [ 260.739617] ? schedule_timeout+0x219/0x356
>> [ 260.739621] ? __next_timer_interrupt+0xf1/0xf1
>> [ 260.739624] ? task_thread.isra.0+0x148/0x3af
>> [ 260.739628] ? task_thread_unbound+0xa/0xa
>> [ 260.739632] ? task_thread_bound+0x7/0x7
>> [ 260.739636] ? ret_from_fork+0x22/0x30
>> [ 260.739647] OOM killer enabled.
>> [ 260.739648] Restarting tasks ... done.
>> [ 260.740077] PM: suspend exit
>>
>> and then a set of similar messages except with s2idle instead of deep.
>>
>> Reverting 5695e51619 ("Merge tag 'io_uring-worker.v3-2021-02-25' of
>> git://git.kernel.dk/linux-block") appears to resolve the issue. I have
>> not yet bisected further. Let me know which troubleshooting steps I
>> should perform next.
>
> Can you try and pull in:
>
> git://git.kernel.dk/linux-block io_uring-5.12
>
> and see if that resolves it? I usually always run -git on my laptop as
> well, but something broke it in the merge window so I need to figure
> out what that is first...
>
> What distro are you running?
You probably want this on top...
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1fdb2b621b51..a763e1b09073 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -567,7 +567,7 @@ static int task_thread(void *data, int index)
worker->task = current;
set_cpus_allowed_ptr(current, cpumask_of_node(wqe->node));
- current->flags |= PF_NO_SETAFFINITY;
+ current->flags |= PF_NO_SETAFFINITY | PF_NOFREEZE;
raw_spin_lock_irq(&wqe->lock);
hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
@@ -722,7 +722,7 @@ static int io_wq_manager(void *data)
sprintf(buf, "iou-mgr-%d", wq->task_pid);
set_task_comm(current, buf);
- current->flags |= PF_IO_WORKER;
+ current->flags |= PF_IO_WORKER | PF_NOFREEZE;
wq->manager = get_task_struct(current);
complete(&wq->started);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2757675ab417..e7aaf56b4dea 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6679,6 +6685,7 @@ static int io_sq_thread(void *data)
set_task_comm(current, buf);
sqd->thread = current;
current->pf_io_worker = NULL;
+ current->flags |= PF_NOFREEZE;
if (sqd->sq_cpu != -1)
set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
--
Jens Axboe
