Subject: Re: [PATCH] block: do not put mq context in blk_mq_alloc_request_hctx
To: Minchan Kim <minchan@kernel.org>
References: <1490851245-32245-1-git-send-email-minchan@kernel.org>
CC: <kernel-team@lge.com>, <linux-block@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
        "Omar Sandoval" <osandov@fb.com>
From: Jens Axboe <axboe@fb.com>
Message-ID: <8787097b-7da5-3ae7-7896-cd08f5376018@fb.com>
Date: Thu, 30 Mar 2017 08:12:28 -0600
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On 03/29/2017 11:20 PM, Minchan Kim wrote:
> In blk_mq_alloc_request_hctx, blk_mq_sched_get_request doesn't
> get sw context so we don't need to put the context with
> blk_mq_put_ctx. Unless, we will see preempt counter underflow.

Good catch, that's definitely a bug. I have applied your patch
for 4.11.

-- 
Jens Axboe