From: axboe@kernel.dk (Jens Axboe)
Subject: Question about stream number
Date: Tue, 15 May 2018 09:23:15 -0600 [thread overview]
Message-ID: <4932a012-1150-f97b-920a-c3618e08aee3@kernel.dk> (raw)
In-Reply-To: <4feb7a21-14b1-be61-a88e-8c7841fae96c@huawei.com>
On 5/15/18 6:46 AM, dingxiang wrote:
> Hi?Jens
> In current NVMe driver, the stream number is set to 4:
>
> /ctrl->nr_streams = min_t(unsigned, ctrl->nssa, BLK_MAX_WRITE_HINTS - 1);/
>
> Why the number is 4 rather than /ctrl->nssa? /
Because we only expose 4 different streams through the fcntl() get/set
rw hint API.
> There is no limit in nvme spec 1.3, can I change it if I need ?
There is a limit, but it's much higher :-)
There's nothing preventing you from changing it. But it would have to be
from an in-kernel user right now, since we don't have a way of passing
in more than 4 separate streams from userspace as it stands.
--
Jens Axboe
next prev parent reply other threads:[~2018-05-15 15:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-08 16:25 [PATCH v3] nvme: add quirk to force medium priority for SQ creation Jens Axboe
2018-05-08 16:35 ` Keith Busch
2018-05-11 17:02 ` Keith Busch
2018-05-11 21:05 ` Jens Axboe
[not found] ` <4feb7a21-14b1-be61-a88e-8c7841fae96c@huawei.com>
2018-05-15 15:23 ` Jens Axboe [this message]
2018-05-09 4:40 ` Christoph Hellwig
2018-05-09 14:05 ` Keith Busch
2018-05-09 14:16 ` Jens Axboe
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