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Date: Thu, 14 Aug 2014 09:33:38 -0600 (MDT)
From: Keith Busch <keith.busch@intel.com>
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To: Jens Axboe <axboe@fb.com>
cc: =?ISO-8859-15?Q?Matias_Bj=F8rling?= <m@bjorling.me>,
        Keith Busch <keith.busch@intel.com>,
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        Christoph Hellwig <hch@infradead.org>,
        Rob Nelson <rlnelson@google.com>, Ming Lei <tom.leiming@gmail.com>
Subject: Re: [PATCH v11] NVMe: Convert to blk-mq
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On Thu, 14 Aug 2014, Jens Axboe wrote:
> On 08/14/2014 02:25 AM, Matias Bjørling wrote:
>> The result is set to BLK_MQ_RQ_QUEUE_ERROR, or am I mistaken?
>
> Looks OK to me, looking at the code, 'result' is initialized to
> BLK_MQ_RQ_QUEUE_BUSY though. Which looks correct, we don't want to error
> on a suspended queue.

My mistake missing how the result was initialized.

> nr_tags must be uninitialized or screwed up somehow, otherwise I don't
> see how that kmalloc() could warn on being too large. Keith, are you
> running with slab debugging? Matias, might be worth trying.

I'm not running with slab debugging. If it's any clue at all, blk-mq is
using 16 of the 31 allocated h/w queues (which is okay as we discussed
earlier), and the oops happens when clearing the first unused queue.

I'll have time to mess with this more today, so I can either help find
the problem or apply a patch if one becomes available.
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