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From: John Garry <john.garry@huawei.com>
To: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
	Dongli Zhang <dongli.zhang@oracle.com>,
	Jens Axboe <axboe@kernel.dk>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	Hannes Reinecke <hare@suse.de>, Daniel Wagner <dwagner@suse.de>
Subject: Re: [PATCH] blk-mq: don't fail driver tag allocation because of inactive hctx
Date: Thu, 4 Jun 2020 15:11:39 +0100	[thread overview]
Message-ID: <83c37a8f-abfa-c1d1-e9d6-ccfdd344edb3@huawei.com> (raw)
In-Reply-To: <20200604130058.GC2336493@T590>

> 
> It isn't related with request->tag, what I meant is that you use
> out-of-tree patch to enable multiple hw queue on hisi_sas, you have
> to make the queue mapping correct, that said the exact queue mapping
> from blk-mq's mapping has to be used, which is built from managed
> interrupt affinity.
> 
> Please collect the following log:
> 
> 1) ./dump-io-irq-affinity $PCI_ID_OF_HBA
> http://people.redhat.com/minlei/tests/tools/dump-io-irq-affinity
> 

I had to hack this a bit for SAS HBA:

kernel version:
Linux ubuntu 5.7.0-next-20200603-16498-gbfbfcda762d5 #405 SMP PREEMPT 
Thu Jun 4 14:19:49 BST 2020 aarch64 aarch64 aarch64 GNU/Linux
-e 	irq 137, cpu list 16-19, effective list 16
-e 	irq 138, cpu list 20-23, effective list 20
-e 	irq 139, cpu list 24-27, effective list 24
-e 	irq 140, cpu list 28-31, effective list 28
-e 	irq 141, cpu list 32-35, effective list 32
-e 	irq 142, cpu list 36-39, effective list 36
-e 	irq 143, cpu list 40-43, effective list 40
-e 	irq 144, cpu list 44-47, effective list 44
-e 	irq 145, cpu list 48-51, effective list 48
-e 	irq 146, cpu list 52-55, effective list 52
-e 	irq 147, cpu list 56-59, effective list 56
-e 	irq 148, cpu list 60-63, effective list 60
-e 	irq 149, cpu list 0-3, effective list 0
-e 	irq 150, cpu list 4-7, effective list 4
-e 	irq 151, cpu list 8-11, effective list 8
-e 	irq 152, cpu list 12-15, effective list 12

> 2) ./dump-qmap /dev/sdN
> http://people.redhat.com/minlei/tests/tools/dump-qmap


queue mapping for /dev/sda
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdb
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdc
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdd
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sde
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdf
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdg
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15
queue mapping for /dev/sdh
	hctx0: default 16 17 18 19
	hctx1: default 20 21 22 23
	hctx2: default 24 25 26 27
	hctx3: default 28 29 30 31
	hctx4: default 32 33 34 35
	hctx5: default 36 37 38 39
	hctx6: default 40 41 42 43
	hctx7: default 44 45 46 47
	hctx8: default 48 49 50 51
	hctx9: default 52 53 54 55
	hctx10: default 56 57 58 59
	hctx11: default 60 61 62 63
	hctx12: default 0 1 2 3
	hctx13: default 4 5 6 7
	hctx14: default 8 9 10 11
	hctx15: default 12 13 14 15

> 
> 
>>
>>   and suggest you to double check
>>> hisi_sas's queue mapping which has to be exactly same with blk-mq's
>>> mapping.
>>>
>>
>> scheduler=none is ok, so I am skeptical of a problem there.
>>
>>>>
>>>>>
>>>>> If yes, can you collect debugfs log after the timeout is triggered?
>>>>
>>>> Same limitation as before - once SCSI timeout happens, SCSI error handling
>>>> kicks in and the shost no longer accepts commands, and, since that same
>>>> shost provides rootfs, becomes unresponsive. But I can try.
>>>
>>> Just wondering why not install two disks in your test machine, :-)
>>
>> The shost becomes unresponsive for all disks. So I could try nfs, but I'm
>> not a fan :)
> 
> Then it will take you extra effort in collecting log, and NFS root
> should have been quite easy to setup, :-)
> 

Should be ...

 >> No, but the LLDD does not use request->tag - it generates its own.
 >
 > Except for wrong queue mapping,  another reason is that the generated
 > tag may not
 > be unique. Either of two may cause such timeout issue when the managed
 > interrupt is
 > active.
 >

Right, but the tag should be unique - it needs to be in the LLDD.

Anyway, I'll continue to debug.

BTW, I'm using linux-next 0306 as baseline. I don't like using next, but 
Linus' master branch yesterday was crashing while booting for me. I need 
to check that again for where master is now.

Thanks


  reply	other threads:[~2020-06-04 14:12 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-03 10:51 [PATCH] blk-mq: don't fail driver tag allocation because of inactive hctx Ming Lei
2020-06-03 11:53 ` Christoph Hellwig
2020-06-03 13:36   ` Ming Lei
2020-06-03 16:16     ` John Garry
2020-06-04  5:22       ` Dongli Zhang
2020-06-04 10:24         ` John Garry
2020-06-04 11:26           ` Ming Lei
2020-06-04 11:50             ` John Garry
2020-06-04 12:08               ` Ming Lei
2020-06-04 12:45                 ` John Garry
2020-06-04 13:00                   ` Ming Lei
2020-06-04 14:11                     ` John Garry [this message]
2020-06-05  0:59                       ` Ming Lei
2020-06-05  7:24                         ` John Garry
2020-06-05  7:31                           ` Ming Lei
2020-06-04 13:28                   ` Ming Lei
2020-06-05  8:33                   ` Ming Lei
2020-06-05  9:27                     ` John Garry
2020-06-05 11:08                       ` John Garry
2020-06-03 18:12     ` Christoph Hellwig

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