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From:   Stanley Chu <chu.stanley@gmail.com>
Date:   Wed, 31 May 2023 17:04:36 +0800
Message-ID: <CAGaU9a_Aoyka-tNvG-WGAEacGgcF38gyHLcTLrK+mL_qGfwRwg@mail.gmail.com>
Subject: Re: blk-mq: check on cpu id when there is only one ctx mapping
To:     Ed Tsai <ed.tsai@mediatek.com>
Cc:     axboe@kernel.dk, kbusch@kernel.org, liusong@linux.alibaba.com,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com,
        peter.wang@mediatek.com, stanley.chu@mediatek.com,
        powen.kao@mediatek.com, alice.chao@mediatek.com,
        naomi.chu@mediatek.com
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On Wed, May 31, 2023 at 4:49=E2=80=AFPM Ed Tsai <ed.tsai@mediatek.com> wrot=
e:
>
> commit f168420 ("blk-mq: don't redirect completion for hctx withs only
> one ctx mapping") When nvme applies a 1:1 mapping of hctx and ctx, there
> will be no remote request.
>
> But for ufs, the submission and completion queues could be asymmetric.
> (e.g. Multiple SQs share one CQ) Therefore, 1:1 mapping of hctx and
> ctx won't complete request on the submission cpu. In this situation,
> this nr_ctx check could violate the QUEUE_FLAG_SAME_FORCE, as a result,
> check on cpu id when there is only one ctx mapping.
>
> Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
> Signed-off-by: Po-Wen Kao <powen.kao@mediatek.com>

Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>