From: Stefan Hajnoczi <stefanha@redhat.com>
To: Alberto Garcia <berto@igalia.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, Stefan Hajnoczi <stefanha@gmail.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] [Qemu-block] [PATCH 00/13] throttle: Allow I/O bursts for a user-defined period of time
Date: Wed, 17 Feb 2016 09:42:13 +0000 [thread overview]
Message-ID: <20160217094213.GA17648@stefanha-x1.localdomain> (raw)
In-Reply-To: <w51bn7gzmw3.fsf@maestria.local.igalia.com>
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On Tue, Feb 16, 2016 at 04:38:04PM +0100, Alberto Garcia wrote:
> On Mon 15 Feb 2016 05:40:29 PM CET, Stefan Hajnoczi wrote:
> > On Fri, Feb 05, 2016 at 12:59:10PM +0200, Alberto Garcia wrote:
> >> - With this series we set "a maximum of X operations/second for a
> >> period of T seconds". If would also be possible to make it "a
> >> maximum of X operations/second up to a total of Y operations". It
> >> would be equivalent (Y = X * T) but I thought the current proposal
> >> makes a more clear API.
> >
> > I find the diagram in the blog post clear. The QEMU code is a little
> > harder to understand, it seems like there are too many variables and
> > special cases. There are 4 core variables:
> >
> > 1. Refill rate (aka avg), e.g. 30 IOPS
> > 2. Max bucket level (aka max * burst_length), e.g. 5.4 million IOPS
> > 3. Burst rate (aka max), e.g. 3000 IOPS
> > 4. Current bucket level
>
> The blog post uses the token bucket algorithm but QEMU uses the leaky
> bucket. They're equivalent, but one is the reverse of the other:
Yes, I find the token bucket approach clearer :).
Stefan
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prev parent reply other threads:[~2016-02-17 9:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-05 10:59 [Qemu-devel] [PATCH 00/13] throttle: Allow I/O bursts for a user-defined period of time Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 01/13] throttle: Make throttle_compute_timer() static Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 02/13] throttle: Make throttle_conflicting() set errp Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 03/13] throttle: Make throttle_max_is_missing_limit() " Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 04/13] throttle: Make throttle_is_valid() " Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 05/13] throttle: Set always an average value when setting a maximum value Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 06/13] throttle: Merge all functions that check the configuration into one Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 07/13] throttle: Use throttle_config_init() to initialize ThrottleConfig Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 08/13] throttle: Add support for burst periods Alberto Garcia
2016-02-16 10:45 ` Kevin Wolf
2016-02-16 14:24 ` Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 09/13] throttle: Add command-line settings to define the " Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 10/13] qapi: Add burst length parameters to block_set_io_throttle Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 11/13] qapi: Add burst length fields to BlockDeviceInfo Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 12/13] throttle: Check that burst_level leaks correctly Alberto Garcia
2016-02-05 10:59 ` [Qemu-devel] [PATCH 13/13] throttle: Test throttle_compute_wait() during bursts Alberto Garcia
2016-02-12 17:19 ` [Qemu-devel] [PATCH 00/13] throttle: Allow I/O bursts for a user-defined period of time Kevin Wolf
2016-02-12 21:50 ` Alberto Garcia
2016-02-15 16:40 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-02-16 15:38 ` Alberto Garcia
2016-02-17 9:42 ` Stefan Hajnoczi [this message]
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