From: weiping zhang <zhangweiping@didichuxing.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: <linux-block@vger.kernel.org>
Subject: Re: [PATCH] blk-mq: only alloc hctx point as many as nr_hw_queues
Date: Fri, 14 Jul 2017 00:30:27 +0800 [thread overview]
Message-ID: <20170713163015.GA10602@bogon.didichuxing.com> (raw)
In-Reply-To: <e03b2bfa-15d3-3d27-15cf-07e65882fc25@kernel.dk>
On Thu, Jul 13, 2017 at 10:14:31AM -0600, Jens Axboe wrote:
> On 07/13/2017 10:10 AM, weiping zhang wrote:
> > one hw queue only has one hctx, reduce it's number same as nr_hw_queues.
>
> What happens if a device registers with eg 4 hw queues, then later
> calls blk_mq_update_nr_hw_queues()?
>
your means, 10 cpu, and device has 10 hw queues, but only register 4,
and then update it to 10, no place store new hctx. Am i understanding
right ? if yes, could you tell me why driver do that ? thanks.
--
weiping
next prev parent reply other threads:[~2017-07-13 16:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-13 16:10 [PATCH] blk-mq: only alloc hctx point as many as nr_hw_queues weiping zhang
2017-07-13 16:14 ` Jens Axboe
2017-07-13 16:30 ` weiping zhang [this message]
2017-07-13 16:38 ` Jens Axboe
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