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Message-ID: <1d3866af-ffca-4f97-914d-8084aca901ab@acm.org>
Date: Thu, 11 Jan 2024 11:22:01 -0800
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Subject: Re: [PATCH v6 1/4] block: Make fair tag sharing configurable
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To: Yu Kuai <yukuai1@huaweicloud.com>, Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
 "Martin K . Petersen" <martin.petersen@oracle.com>,
 Christoph Hellwig <hch@lst.de>, Ming Lei <ming.lei@redhat.com>,
 Keith Busch <kbusch@kernel.org>,
 Damien Le Moal <damien.lemoal@opensource.wdc.com>,
 Ed Tsai <ed.tsai@mediatek.com>, Matthias Brugger <matthias.bgg@gmail.com>,
 AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
 "yukuai (C)" <yukuai3@huawei.com>
References: <20231130193139.880955-1-bvanassche@acm.org>
 <20231130193139.880955-2-bvanassche@acm.org>
 <58f50403-fcc9-ec11-f52b-f11ced3d2652@huaweicloud.com>
 <8372f2d0-b695-4af4-90e6-e35b86e3b844@acm.org>
 <c1658336-f48e-5688-f0c2-f325fd5696c3@huaweicloud.com>
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <c1658336-f48e-5688-f0c2-f325fd5696c3@huaweicloud.com>
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On 12/25/23 04:51, Yu Kuai wrote:
> Are you still intrested in this patchset? I really want this switch in
> our product as well.
> 
> If so, how do you think about following changes, a new field in
> blk_mq_tag_set will make synchronization much eaiser.
Do you perhaps see the new field as an alternative for the
BLK_MQ_F_DISABLE_FAIR_TAG_SHARING flag? I'm not sure that would be an
improvement. hctx_may_queue() is called from the hot path. Using the
'flags' field will make it easier for the compiler to optimize that
function compared to using a new structure member.

Thanks,

Bart.