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? -- Jens Axboe