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Date:   Sun, 16 Dec 2018 17:16:50 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        Jeff Moyer <jmoyer@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>,
        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 3/4] blk-mq: deal with shared queue mapping reliably
Message-ID: <20181216161650.GD9957@lst.de>
References: <20181216022517.26650-1-ming.lei@redhat.com> <20181216022517.26650-4-ming.lei@redhat.com>
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On Sun, Dec 16, 2018 at 10:25:16AM +0800, Ming Lei wrote:
> This patch sets map->nr_queues as zero explictly if there is zero
> queues for such queue type, then blk_mq_map_swqueue() can become
> more robust to deal with shared mappings.

This looks a lot more clumsy than what we had before, can you explain
what additional robustnes it buys us?