On 3/1/21 6:25 PM, Jens Axboe wrote:
> 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...
And if you've verified that that one works OK, can you try this variant
instead?
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1fdb2b621b51..fe004cf93c4b 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -16,6 +16,7 @@
#include <linux/rculist_nulls.h>
#include <linux/cpu.h>
#include <linux/tracehook.h>
+#include <linux/freezer.h>
#include "../kernel/sched/sched.h"
#include "io-wq.h"
@@ -480,6 +481,7 @@ static int io_wqe_worker(void *data)
io_worker_start(worker);
while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
+ try_to_freeze();
set_current_state(TASK_INTERRUPTIBLE);
loop:
raw_spin_lock_irq(&wqe->lock);
@@ -731,6 +733,7 @@ static int io_wq_manager(void *data)
set_current_state(TASK_INTERRUPTIBLE);
io_wq_check_workers(wq);
schedule_timeout(HZ);
+ try_to_freeze();
if (fatal_signal_pending(current))
set_bit(IO_WQ_BIT_EXIT, &wq->state);
} while (!test_bit(IO_WQ_BIT_EXIT, &wq->state));
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2757675ab417..03c42f1f9862 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -74,13 +74,11 @@
#include <linux/fsnotify.h>
#include <linux/fadvise.h>
#include <linux/eventpoll.h>
-#include <linux/fs_struct.h>
#include <linux/splice.h>
#include <linux/task_work.h>
#include <linux/pagemap.h>
#include <linux/io_uring.h>
-#include <linux/blk-cgroup.h>
-#include <linux/audit.h>
+#include <linux/freezer.h>
#define CREATE_TRACE_POINTS
#include <trace/events/io_uring.h>
@@ -6744,6 +6748,7 @@ static int io_sq_thread(void *data)
io_ring_set_wakeup_flag(ctx);
schedule();
+ try_to_freeze();
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
io_ring_clear_wakeup_flag(ctx);
}
--
Jens Axboe
