Re: Observing an fio hang with RNBD device in the latest v5.10.78 Linux kernel

Haris Iqbal
2021-11-11T08:39:04Z

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On Wed, Nov 10, 2021 at 2:39 AM Ming Lei <ming.lei@redhat.com> wrote:
>
> Hello Haris,
>
> On Tue, Nov 09, 2021 at 10:32:32AM +0100, Haris Iqbal wrote:
> > Hi,
> >
> > We are observing an fio hang with the latest v5.10.78 Linux kernel
> > version with RNBD. The setup is as follows,
> >
> > On the server side, 16 nullblk devices.
> > On the client side, map those 16 block devices through RNBD-RTRS.
> > Change the scheduler for those RNBD block devices to mq-deadline.
> >
> > Run fios with the following configuration.
> >
> > [global]
> > description=Emulation of Storage Server Access Pattern
> > bssplit=512/20:1k/16:2k/9:4k/12:8k/19:16k/10:32k/8:64k/4
> > fadvise_hint=0
> > rw=randrw:2
> > direct=1
> > random_distribution=zipf:1.2
> > time_based=1
> > runtime=60
> > ramp_time=1
> > ioengine=libaio
> > iodepth=128
> > iodepth_batch_submit=128
> > iodepth_batch_complete=128
> > numjobs=1
> > group_reporting
> >
> >
> > [job1]
> > filename=/dev/rnbd0
> > [job2]
> > filename=/dev/rnbd1
> > [job3]
> > filename=/dev/rnbd2
> > [job4]
> > filename=/dev/rnbd3
> > [job5]
> > filename=/dev/rnbd4
> > [job6]
> > filename=/dev/rnbd5
> > [job7]
> > filename=/dev/rnbd6
> > [job8]
> > filename=/dev/rnbd7
> > [job9]
> > filename=/dev/rnbd8
> > [job10]
> > filename=/dev/rnbd9
> > [job11]
> > filename=/dev/rnbd10
> > [job12]
> > filename=/dev/rnbd11
> > [job13]
> > filename=/dev/rnbd12
> > [job14]
> > filename=/dev/rnbd13
> > [job15]
> > filename=/dev/rnbd14
> > [job16]
> > filename=/dev/rnbd15
> >
> > Some of the fio threads hangs and the fio never finishes.
> >
> > fio fio.ini
> > job1: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job2: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job3: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job4: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job5: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job6: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job7: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job8: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job9: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job10: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job11: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job12: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job13: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job14: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job15: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > job16: (g=0): rw=randrw, bs=(R) 512B-64.0KiB, (W) 512B-64.0KiB, (T)
> > 512B-64.0KiB, ioengine=libaio, iodepth=128
> > fio-3.12
> > Starting 16 processes
> > Jobs: 16 (f=12):
> > [m(3),/(2),m(5),/(1),m(1),/(1),m(3)][0.0%][r=130MiB/s,w=130MiB/s][r=14.7k,w=14.7k
> > IOPS][eta 04d:07h:4
> > Jobs: 15 (f=11):
> > [m(3),/(2),m(5),/(1),_(1),/(1),m(3)][51.2%][r=7395KiB/s,w=6481KiB/s][r=770,w=766
> > IOPS][eta 01m:01s]
> > Jobs: 15 (f=11): [m(3),/(2),m(5),/(1),_(1),/(1),m(3)][52.7%][eta 01m:01s]
> >
> > We checked the block devices, and there are requests waiting in their
> > fifo (not on all devices, just few whose corresponding fio threads are
> > hung).
> >
> > $ cat /sys/kernel/debug/block/rnbd0/sched/read_fifo_list
> > 00000000ce398aec {.op=READ, .cmd_flags=,
> > .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1,
> > .internal_tag=209}
> > 000000005ec82450 {.op=READ, .cmd_flags=,
> > .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1,
> > .internal_tag=210}
> >
> > $ cat /sys/kernel/debug/block/rnbd0/sched/write_fifo_list
> > 000000000c1557f5 {.op=WRITE, .cmd_flags=SYNC|IDLE,
> > .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1,
> > .internal_tag=195}
> > 00000000fc6bfd98 {.op=WRITE, .cmd_flags=SYNC|IDLE,
> > .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1,
> > .internal_tag=199}
> > 000000009ef7c802 {.op=WRITE, .cmd_flags=SYNC|IDLE,
> > .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1,
> > .internal_tag=217}
>
> Can you post the whole debugfs log for rnbd0?
>
> (cd /sys/kernel/debug/block/rnbd0 && find . -type f -exec grep -aH . {} \;)

Attached the log file.

>
> >
> >
> > Potential points which fixes the hang
> >
> > 1) Using no scheduler (none) on the client side RNBD block devices
> > results in no hang.
> >
> > 2) In the fio config, changing the line "iodepth_batch_complete=128"
> > to the following fixes the hang,
> > iodepth_batch_complete_min=1
> > iodepth_batch_complete_max=128
> > OR,
> > iodepth_batch_complete=0
> >
> > 3) We also tracked down the version from which the hang started. The
> > hang started with v5.10.50, and the following commit was one which
> > results in the hang
> >
> > commit 512106ae2355813a5eb84e8dc908628d52856890
> > Author: Ming Lei <ming.lei@redhat.com>
> > Date: Fri Jun 25 10:02:48 2021 +0800
> >
> > blk-mq: update hctx->dispatch_busy in case of real scheduler
> >
> > [ Upstream commit cb9516be7708a2a18ec0a19fe3a225b5b3bc92c7 ]
> >
> > Commit 6e6fcbc27e77 ("blk-mq: support batching dispatch in case of io")
> > starts to support io batching submission by using hctx->dispatch_busy.
> >
> > However, blk_mq_update_dispatch_busy() isn't changed to update
> > hctx->dispatch_busy
> > in that commit, so fix the issue by updating hctx->dispatch_busy in case
> > of real scheduler.
> >
> > Reported-by: Jan Kara <jack@suse.cz>
> > Reviewed-by: Jan Kara <jack@suse.cz>
> > Fixes: 6e6fcbc27e77 ("blk-mq: support batching dispatch in case of io")
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > Link: https://lore.kernel.org/r/20210625020248.1630497-1-ming.lei@redhat.com
> > Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > Signed-off-by: Sasha Levin <sashal@kernel.org>
> >
> > diff --git a/block/blk-mq.c b/block/blk-mq.c
> > index 00d6ed2fe812..a368eb6dc647 100644
> > --- a/block/blk-mq.c
> > +++ b/block/blk-mq.c
> > @@ -1242,9 +1242,6 @@ static void blk_mq_update_dispatch_busy(struct
> > blk_mq_hw_ctx *hctx, bool busy)
> > {
> > unsigned int ewma;
> >
> > - if (hctx->queue->elevator)
> > - return;
> > -
> > ewma = hctx->dispatch_busy;
> >
> > if (!ewma && !busy)
> >
> > We reverted the commit and tested and there is no hang.
> >
> > 4) Lastly, we tested newer version like 5.13, and there is NO hang in
> > that also. Hence, probably some other change fixed it.
>
> Can you observe the issue on v5.10? Maybe there is one pre-patch of commit cb9516be7708
> ("blk-mq: update hctx->dispatch_busy in case of real scheduler merged")
> which is missed to 5.10.y.

If you mean v5.10.0, then no, I see no hang there. As I mentioned
before, there is no hang till v5.10.49.

>
> And not remember that there is fix for commit cb9516be7708 in mainline.
>
> commit cb9516be7708 is merged to v5.14, instead of v5.13, did you test v5.14 or v5.15?
>
> BTW, commit cb9516be7708 should just affect performance, not supposed to cause
> hang.

True. It does look like that from the small code change.

I wasn't able to test in v5.14 and v5.15 because we are seeing some
other errors in those versions, most probably related to the
rdma-core/rxe driver.

>
> Thanks,
> Ming
>

[-- Attachment #2: debugfslog_rnbd0 --]
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./sched/starved:0
./sched/batching:7
./sched/write_next_rq:0000000094da63eb {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=35}
./sched/write_fifo_list:0000000094da63eb {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=35}
./sched/write_fifo_list:000000005bca28b9 {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=41}
./sched/write_fifo_list:0000000094151866 {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=43}
./sched/write_fifo_list:00000000b8b87018 {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=49}
./sched/write_fifo_list:00000000650ab2f5 {.op=WRITE, .cmd_flags=SYNC|IDLE, .rq_flags=SORTED|ELVPRIV|IO_STAT|HASHED, .state=idle, .tag=-1, .internal_tag=2}
./rqos/wbt/wb_background:4
./rqos/wbt/wb_normal:8
./rqos/wbt/unknown_cnt:0
./rqos/wbt/min_lat_nsec:2000000
./rqos/wbt/inflight:0: inflight 0
./rqos/wbt/inflight:1: inflight 0
./rqos/wbt/inflight:2: inflight 0
./rqos/wbt/id:0
./rqos/wbt/enabled:1
./rqos/wbt/curr_win_nsec:0
./hctx3/cpu3/completed:6987 0
./hctx3/cpu3/merged:0
./hctx3/cpu3/dispatched:6987 0
./hctx3/type:default
./hctx3/dispatch_busy:5
./hctx3/active:0
./hctx3/run:7514
./hctx3/queued:6987
./hctx3/dispatched: 0 4851
./hctx3/dispatched: 1 2685
./hctx3/dispatched: 2 217
./hctx3/dispatched: 4 270
./hctx3/dispatched: 8 163
./hctx3/dispatched: 16 31
./hctx3/dispatched: 32+ 0
./hctx3/io_poll:considered=0
./hctx3/io_poll:invoked=0
./hctx3/io_poll:success=0
./hctx3/sched_tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/sched_tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/sched_tags:nr_tags=256
./hctx3/sched_tags:nr_reserved_tags=0
./hctx3/sched_tags:active_queues=0
./hctx3/sched_tags:bitmap_tags:
./hctx3/sched_tags:depth=256
./hctx3/sched_tags:busy=0
./hctx3/sched_tags:cleared=195
./hctx3/sched_tags:bits_per_word=64
./hctx3/sched_tags:map_nr=4
./hctx3/sched_tags:alloc_hint={6, 245, 41, 141}
./hctx3/sched_tags:wake_batch=8
./hctx3/sched_tags:wake_index=0
./hctx3/sched_tags:ws_active=0
./hctx3/sched_tags:ws={
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx3/sched_tags:}
./hctx3/sched_tags:round_robin=0
./hctx3/sched_tags:min_shallow_depth=4294967295
./hctx3/tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/tags_bitmap:00000020: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/tags_bitmap:00000030: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx3/tags:nr_tags=512
./hctx3/tags:nr_reserved_tags=0
./hctx3/tags:active_queues=0
./hctx3/tags:bitmap_tags:
./hctx3/tags:depth=512
./hctx3/tags:busy=0
./hctx3/tags:cleared=458
./hctx3/tags:bits_per_word=64
./hctx3/tags:map_nr=8
./hctx3/tags:alloc_hint={168, 253, 246, 369}
./hctx3/tags:wake_batch=8
./hctx3/tags:wake_index=7
./hctx3/tags:ws_active=0
./hctx3/tags:ws={
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags: {.wait_cnt=8, .wait=inactive},
./hctx3/tags:}
./hctx3/tags:round_robin=0
./hctx3/tags:min_shallow_depth=4294967295
./hctx3/ctx_map:00000000: 00
./hctx3/flags:alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED
./hctx2/cpu2/completed:4585 0
./hctx2/cpu2/merged:0
./hctx2/cpu2/dispatched:4590 0
./hctx2/type:default
./hctx2/dispatch_busy:5
./hctx2/active:0
./hctx2/run:4644
./hctx2/queued:4590
./hctx2/dispatched: 0 2761
./hctx2/dispatched: 1 1966
./hctx2/dispatched: 2 119
./hctx2/dispatched: 4 153
./hctx2/dispatched: 8 79
./hctx2/dispatched: 16 25
./hctx2/dispatched: 32+ 4
./hctx2/io_poll:considered=0
./hctx2/io_poll:invoked=0
./hctx2/io_poll:success=0
./hctx2/sched_tags_bitmap:00000000: 0400 0000 080a 0200 0000 0000 0000 0000
./hctx2/sched_tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx2/sched_tags:nr_tags=256
./hctx2/sched_tags:nr_reserved_tags=0
./hctx2/sched_tags:active_queues=0
./hctx2/sched_tags:bitmap_tags:
./hctx2/sched_tags:depth=256
./hctx2/sched_tags:busy=5
./hctx2/sched_tags:cleared=222
./hctx2/sched_tags:bits_per_word=64
./hctx2/sched_tags:map_nr=4
./hctx2/sched_tags:alloc_hint={209, 91, 50, 218}
./hctx2/sched_tags:wake_batch=8
./hctx2/sched_tags:wake_index=0
./hctx2/sched_tags:ws_active=0
./hctx2/sched_tags:ws={
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx2/sched_tags:}
./hctx2/sched_tags:round_robin=0
./hctx2/sched_tags:min_shallow_depth=4294967295
./hctx2/tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx2/tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx2/tags_bitmap:00000020: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx2/tags_bitmap:00000030: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx2/tags:nr_tags=512
./hctx2/tags:nr_reserved_tags=0
./hctx2/tags:active_queues=0
./hctx2/tags:bitmap_tags:
./hctx2/tags:depth=512
./hctx2/tags:busy=0
./hctx2/tags:cleared=477
./hctx2/tags:bits_per_word=64
./hctx2/tags:map_nr=8
./hctx2/tags:alloc_hint={510, 327, 106, 507}
./hctx2/tags:wake_batch=8
./hctx2/tags:wake_index=4
./hctx2/tags:ws_active=0
./hctx2/tags:ws={
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags: {.wait_cnt=8, .wait=inactive},
./hctx2/tags:}
./hctx2/tags:round_robin=0
./hctx2/tags:min_shallow_depth=4294967295
./hctx2/ctx_map:00000000: 00
./hctx2/flags:alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED
./hctx1/cpu1/completed:5742 0
./hctx1/cpu1/merged:0
./hctx1/cpu1/dispatched:5742 0
./hctx1/type:default
./hctx1/dispatch_busy:7
./hctx1/active:0
./hctx1/run:5574
./hctx1/queued:5742
./hctx1/dispatched: 0 3444
./hctx1/dispatched: 1 2088
./hctx1/dispatched: 2 193
./hctx1/dispatched: 4 240
./hctx1/dispatched: 8 121
./hctx1/dispatched: 16 31
./hctx1/dispatched: 32+ 0
./hctx1/io_poll:considered=0
./hctx1/io_poll:invoked=0
./hctx1/io_poll:success=0
./hctx1/sched_tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/sched_tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/sched_tags:nr_tags=256
./hctx1/sched_tags:nr_reserved_tags=0
./hctx1/sched_tags:active_queues=0
./hctx1/sched_tags:bitmap_tags:
./hctx1/sched_tags:depth=256
./hctx1/sched_tags:busy=0
./hctx1/sched_tags:cleared=228
./hctx1/sched_tags:bits_per_word=64
./hctx1/sched_tags:map_nr=4
./hctx1/sched_tags:alloc_hint={15, 176, 25, 203}
./hctx1/sched_tags:wake_batch=8
./hctx1/sched_tags:wake_index=0
./hctx1/sched_tags:ws_active=0
./hctx1/sched_tags:ws={
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx1/sched_tags:}
./hctx1/sched_tags:round_robin=0
./hctx1/sched_tags:min_shallow_depth=4294967295
./hctx1/tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/tags_bitmap:00000020: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/tags_bitmap:00000030: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx1/tags:nr_tags=512
./hctx1/tags:nr_reserved_tags=0
./hctx1/tags:active_queues=0
./hctx1/tags:bitmap_tags:
./hctx1/tags:depth=512
./hctx1/tags:busy=0
./hctx1/tags:cleared=512
./hctx1/tags:bits_per_word=64
./hctx1/tags:map_nr=8
./hctx1/tags:alloc_hint={253, 248, 391, 272}
./hctx1/tags:wake_batch=8
./hctx1/tags:wake_index=6
./hctx1/tags:ws_active=0
./hctx1/tags:ws={
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags: {.wait_cnt=8, .wait=inactive},
./hctx1/tags:}
./hctx1/tags:round_robin=0
./hctx1/tags:min_shallow_depth=4294967295
./hctx1/ctx_map:00000000: 00
./hctx1/flags:alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED
./hctx0/cpu0/completed:9424 0
./hctx0/cpu0/merged:0
./hctx0/cpu0/dispatched:9424 0
./hctx0/type:default
./hctx0/dispatch_busy:7
./hctx0/active:0
./hctx0/run:9545
./hctx0/queued:9424
./hctx0/dispatched: 0 6052
./hctx0/dispatched: 1 3435
./hctx0/dispatched: 2 272
./hctx0/dispatched: 4 374
./hctx0/dispatched: 8 216
./hctx0/dispatched: 16 49
./hctx0/dispatched: 32+ 1
./hctx0/io_poll:considered=0
./hctx0/io_poll:invoked=0
./hctx0/io_poll:success=0
./hctx0/sched_tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/sched_tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/sched_tags:nr_tags=256
./hctx0/sched_tags:nr_reserved_tags=0
./hctx0/sched_tags:active_queues=0
./hctx0/sched_tags:bitmap_tags:
./hctx0/sched_tags:depth=256
./hctx0/sched_tags:busy=0
./hctx0/sched_tags:cleared=233
./hctx0/sched_tags:bits_per_word=64
./hctx0/sched_tags:map_nr=4
./hctx0/sched_tags:alloc_hint={196, 152, 174, 2}
./hctx0/sched_tags:wake_batch=8
./hctx0/sched_tags:wake_index=0
./hctx0/sched_tags:ws_active=0
./hctx0/sched_tags:ws={
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags: {.wait_cnt=8, .wait=inactive},
./hctx0/sched_tags:}
./hctx0/sched_tags:round_robin=0
./hctx0/sched_tags:min_shallow_depth=4294967295
./hctx0/tags_bitmap:00000000: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/tags_bitmap:00000010: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/tags_bitmap:00000020: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/tags_bitmap:00000030: 0000 0000 0000 0000 0000 0000 0000 0000
./hctx0/tags:nr_tags=512
./hctx0/tags:nr_reserved_tags=0
./hctx0/tags:active_queues=0
./hctx0/tags:bitmap_tags:
./hctx0/tags:depth=512
./hctx0/tags:busy=0
./hctx0/tags:cleared=511
./hctx0/tags:bits_per_word=64
./hctx0/tags:map_nr=8
./hctx0/tags:alloc_hint={116, 124, 315, 478}
./hctx0/tags:wake_batch=8
./hctx0/tags:wake_index=5
./hctx0/tags:ws_active=0
./hctx0/tags:ws={
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags: {.wait_cnt=8, .wait=inactive},
./hctx0/tags:}
./hctx0/tags:round_robin=0
./hctx0/tags:min_shallow_depth=4294967295
./hctx0/ctx_map:00000000: 00
./hctx0/flags:alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED
./write_hints:hint0: 0
./write_hints:hint1: 0
./write_hints:hint2: 0
./write_hints:hint3: 0
./write_hints:hint4: 0
./state:SAME_COMP|NONROT|IO_STAT|SAME_FORCE|INIT_DONE|WC|FUA|STATS|REGISTERED|NOWAIT
./pm_only:0
./poll_stat:read (512 Bytes): samples=0
./poll_stat:write (512 Bytes): samples=0
./poll_stat:read (1024 Bytes): samples=0
./poll_stat:write (1024 Bytes): samples=0
./poll_stat:read (2048 Bytes): samples=0
./poll_stat:write (2048 Bytes): samples=0
./poll_stat:read (4096 Bytes): samples=0
./poll_stat:write (4096 Bytes): samples=0
./poll_stat:read (8192 Bytes): samples=0
./poll_stat:write (8192 Bytes): samples=0
./poll_stat:read (16384 Bytes): samples=0
./poll_stat:write (16384 Bytes): samples=0
./poll_stat:read (32768 Bytes): samples=0
./poll_stat:write (32768 Bytes): samples=0
./poll_stat:read (65536 Bytes): samples=0
./poll_stat:write (65536 Bytes): samples=0