From: Jens Axboe <axboe@kernel.dk>
To: Josef Bacik <josef@toxicpanda.com>,
kernel-team@fb.com, linux-block@vger.kernel.org
Subject: Re: [PATCH] block: allow us to change max_segments on the fly
Date: Mon, 3 Apr 2017 13:15:36 -0600 [thread overview]
Message-ID: <9a782a78-7842-db93-2065-22081d16ab1d@kernel.dk> (raw)
In-Reply-To: <1491246798-1774-1-git-send-email-jbacik@fb.com>
On 04/03/2017 01:13 PM, Josef Bacik wrote:
> For things like NBD we want to be able to experiment with different
> sized requests going over the wire. Half of our limit is controled by
> max_sectors_kb, but the other half is how many bvec's we can cram into a
> request, which is controlled by max_segments. Changing this sysfs knob
> to be writeable allows us to be able to control our io limits more
> precisely.
This is a hw setting for most drivers, we can't make it user settable.
If you want it user settable, you'd have to split it in a hw and user
setting.
--
Jens Axboe
prev parent reply other threads:[~2017-04-03 19:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-03 19:13 [PATCH] block: allow us to change max_segments on the fly Josef Bacik
2017-04-03 19:15 ` Jens Axboe [this message]
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