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.
Thanks,
Alex.
