On Tue, Nov 19, 2013 at 09:05:09AM -0700, Jens Axboe wrote:
> On Tue, Nov 19 2013, Christoph Hellwig wrote:
> > On Tue, Nov 19, 2013 at 07:02:18PM +1100, Dave Chinner wrote:
> > > I have no idea if it's related to the above hang, but either way
> > > breaking iostat is a major regression....
> >
> > Both of them are most likely due to the conversion of virtio_blk
> > to the blk-mq code.
> >
> > I've not seen the hang in my heavy xfstests testing, but that was a
> > slightly different codebase than what finally got in, so I'll try
> > to reproduce it once I get some spare QA cycles.
>
> Thanks! Dave, if you still have it in that state, can you dump the
> contents of /sys/block/<devs>/mq/ for the device/devices that are hung?
# find /sys/block/vdb/mq -type f -print -exec cat {} \;
/sys/block/vdb/mq/0/run
1313835
/sys/block/vdb/mq/0/cpu0/completed
546857 207203
/sys/block/vdb/mq/0/cpu0/rq_list
CTX pending:
/sys/block/vdb/mq/0/cpu0/merged
0
/sys/block/vdb/mq/0/cpu0/dispatched
257733 496352
/sys/block/vdb/mq/0/cpu1/completed
547714 200741
/sys/block/vdb/mq/0/cpu1/rq_list
CTX pending:
/sys/block/vdb/mq/0/cpu1/merged
0
/sys/block/vdb/mq/0/cpu1/dispatched
262114 486381
/sys/block/vdb/mq/0/tags
nr_tags=66, reserved_tags=2, batch_move=16, max_cache=32
nr_free=0, nr_reserved=1
cpu00: nr_free=0
cpu01: nr_free=0
/sys/block/vdb/mq/0/ipi_redirect
0
/sys/block/vdb/mq/0/queued
1384795
/sys/block/vdb/mq/0/dispatched
0 194596
1 1022691
2 68540
4 10138
8 7686
16 10234
32 0
64 0
128 0
256 0
/sys/block/vdb/mq/0/pending
HCTX pending:
#
It looks like it's hung because of this:
/sys/block/vdb/mq/0/tags
nr_tags=66, reserved_tags=2, batch_move=16, max_cache=32
nr_free=0, nr_reserved=1
cpu00: nr_free=0
cpu01: nr_free=0
No free tags in teh pool, nor any free tags in the per-cpu
magazines. Perhaps there is a leak somewhere?
Cheers,
Dave.
--
Dave Chinner
da...@fromorbit.com
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