From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@fb.com>
Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org,
linux-block@vger.kernel.org, hch@lst.de
Subject: Re: [PATCH 3/4] blk-mq: implement hybrid poll mode for sync O_DIRECT
Date: Wed, 2 Nov 2016 15:54:59 +0100 [thread overview]
Message-ID: <20161102145459.GD13964@lst.de> (raw)
In-Reply-To: <1478034325-28232-4-git-send-email-axboe@fb.com>
On Tue, Nov 01, 2016 at 03:05:24PM -0600, Jens Axboe wrote:
> This patch enables a hybrid polling mode. Instead of polling after IO
> submission, we can induce an artificial delay, and then poll after that.
> For example, if the IO is presumed to complete in 8 usecs from now, we
> can sleep for 4 usecs, wake up, and then do our polling. This still puts
> a sleep/wakeup cycle in the IO path, but instead of the wakeup happening
> after the IO has completed, it'll happen before. With this hybrid
> scheme, we can achieve big latency reductions while still using the same
> (or less) amount of CPU.
>
> Signed-off-by: Jens Axboe <axboe@fb.com>
This looks very nice. I'll need to run some tests before giving the
formal ACK, though.
next prev parent reply other threads:[~2016-11-02 14:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-01 21:05 [PATCHSET] block: IO polling improvements Jens Axboe
2016-11-01 21:05 ` [PATCH 1/4] block: add scalable completion tracking of requests Jens Axboe
2016-11-01 22:25 ` Johannes Thumshirn
2016-11-01 22:25 ` Johannes Thumshirn
2016-11-02 5:37 ` Jens Axboe
2016-11-02 14:52 ` Christoph Hellwig
2016-11-02 14:55 ` Jens Axboe
2016-11-02 14:55 ` Jens Axboe
2016-11-02 14:59 ` Christoph Hellwig
2016-11-03 11:17 ` Ming Lei
2016-11-03 13:38 ` Jens Axboe
2016-11-03 14:57 ` Ming Lei
2016-11-03 16:55 ` Jens Axboe
2016-11-04 23:13 ` Ming Lei
2016-11-05 20:49 ` Jens Axboe
2016-11-05 20:59 ` Jens Axboe
2016-11-03 14:10 ` Bart Van Assche
2016-11-03 14:18 ` Jens Axboe
2016-11-03 14:18 ` Jens Axboe
2016-11-01 21:05 ` [PATCH 2/4] block: move poll code to blk-mq Jens Axboe
2016-11-02 14:54 ` Christoph Hellwig
2016-11-01 21:05 ` [PATCH 3/4] blk-mq: implement hybrid poll mode for sync O_DIRECT Jens Axboe
2016-11-02 14:54 ` Christoph Hellwig [this message]
2016-11-03 12:27 ` Ming Lei
2016-11-03 13:41 ` Jens Axboe
2016-11-03 14:01 ` Bart Van Assche
2016-11-03 14:15 ` Jens Axboe
2016-11-03 14:15 ` Jens Axboe
2016-11-01 21:05 ` [PATCH 4/4] blk-mq: make the polling code adaptive Jens Axboe
2016-11-02 14:51 ` [PATCHSET] block: IO polling improvements Christoph Hellwig
2016-11-02 14:54 ` Jens Axboe
2016-11-02 14:54 ` Jens Axboe
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