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Subject: Re: [PATCH V2 2/2] block: drain blkcg part of request_queue in
 blk_cleanup_queue()
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@fb.com>,
        linux-block@vger.kernel.org, Christoph Hellwig <hch@infradead.org>
Cc: Omar Sandoval <osandov@fb.com>,
        Bart Van Assche <bart.vanassche@sandisk.com>,
        Hannes Reinecke <hare@suse.com>,
        Wen Xiong <wenxiong@us.ibm.com>
References: <20171123044800.25251-1-ming.lei@redhat.com>
 <20171123044800.25251-3-ming.lei@redhat.com>
From: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Date: Mon, 27 Nov 2017 10:15:31 -0200
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In-Reply-To: <20171123044800.25251-3-ming.lei@redhat.com>
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On 11/23/2017 02:48 AM, Ming Lei wrote:
> Now once blk_freeze_queue() returns, all requests(in-queue and pending)
> can be drained, but we still need to drain blkcg part of request_queue
> for both blk-mq and legacy, so this patch calls blkcg_drain_queue()
> explicitely in blk_cleanup_queue() to do that.
> 
> Then the __blk_drain_queue() in blk_cleanup_queue() can be covered by both
> blk_freeze_queue() and blkcg_drain_queue(), and tasks blocked in get_request()
> are waken up in blk_set_queue_dying() too, so remove it from blk_cleanup_queue().
> 
> Cc: Wen Xiong<wenxiong@us.ibm.com>
> Cc: Mauricio Faria de Oliveira<mauricfo@linux.vnet.ibm.com>
> Signed-off-by: Ming Lei<ming.lei@redhat.com>

Tested-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>

All disk pull tests completed successfully without I/O hangs (24 disks).


-- 
Mauricio Faria de Oliveira
IBM Linux Technology Center