From: Christoph Hellwig <hch@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Andrzej Jakowski <andrzej.jakowski@linux.intel.com>,
song@kernel.org, linux-block@vger.kernel.org,
linux-raid@vger.kernel.org,
Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Subject: Re: [PATCH 1/2] block: introduce polling on bio level
Date: Thu, 30 Jan 2020 22:35:27 -0800 [thread overview]
Message-ID: <20200131063527.GC6267@infradead.org> (raw)
In-Reply-To: <de27b35e-a713-dc9d-5164-0397c0dff285@kernel.dk>
On Wed, Jan 29, 2020 at 09:01:49PM -0700, Jens Axboe wrote:
> blk_poll() used to be a pointer in the queue, but since we just had
> one implementation, we got rid of it. Might make sense to
> reintroduce that, and just make it an optimized indirect call. I
> think that would be prettier than add the bio hack in the middle of
> it, and you're having to add a queue pointer anyway.
Well, the other reason is to avoid an indirect call for the blk-mq
case, which are fairly expensive. In fact I'm pretty sure we avoid
indirect calls from the bio layer into blk-mq entirely for the fast
path at the moment, and it would be great to keep it that way.
next prev parent reply other threads:[~2020-01-31 6:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-26 4:41 [PATCH 0/2] Enable polling on stackable devices Andrzej Jakowski
2020-01-26 4:41 ` [PATCH 1/2] block: introduce polling on bio level Andrzej Jakowski
2020-01-30 4:01 ` Jens Axboe
2020-01-31 6:35 ` Christoph Hellwig [this message]
2020-02-01 4:41 ` Jens Axboe
2020-01-31 6:34 ` Christoph Hellwig
2020-01-31 18:51 ` Andrzej Jakowski
2020-02-01 8:20 ` Christoph Hellwig
2020-01-26 4:41 ` [PATCH 2/2] md: enable io polling Andrzej Jakowski
2020-01-31 6:36 ` Christoph Hellwig
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