From: Chris Friesen <chris.friesen@windriver.com>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] is there a limit on the number of in-flight I/O operations?
Date: Sat, 19 Jul 2014 00:27:16 -0600 [thread overview]
Message-ID: <53CA0FC4.8080802@windriver.com> (raw)
In-Reply-To: <53CA06ED.1090102@redhat.com>
On 07/18/2014 11:49 PM, Paolo Bonzini wrote:
> Il 19/07/2014 00:48, Chris Friesen ha scritto:
>>>>
>>>
>>> I forgot about "-drive ...,iops_max=NNN". :)
>>
>> I'm not sure it's actually useful though, since it specifies the max IO
>> operations per second, not the maximum number of in-flight operations.
>
> No, that's "-drive iops=NNN". QEMU implements a leaky bucket algorithm,
> where "iops_max" gives the size of the bucket and "iops" gives the
> refill rate.
Does it track in-flight operations though? Or just how many operations
can be requested in a given amount of time?
If it tracks how many operations can be requested, then if the "iops"
parameter is larger than what the server can maintain then the number of
in-flight operations could still grow indefinitely.
I suppose I'll have to check the code. :)
Chris
next prev parent reply other threads:[~2014-07-19 6:27 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-18 14:58 [Qemu-devel] is there a limit on the number of in-flight I/O operations? Chris Friesen
2014-07-18 15:24 ` Paolo Bonzini
2014-07-18 16:22 ` Chris Friesen
2014-07-18 20:13 ` Paolo Bonzini
2014-07-18 22:48 ` Chris Friesen
2014-07-19 5:49 ` Paolo Bonzini
2014-07-19 6:27 ` Chris Friesen [this message]
2014-07-19 7:23 ` Paolo Bonzini
2014-07-19 8:45 ` Benoît Canet
2014-07-21 14:59 ` Chris Friesen
2014-07-21 15:15 ` Benoît Canet
2014-07-21 15:35 ` Chris Friesen
2014-07-21 15:54 ` Benoît Canet
2014-07-21 16:10 ` Benoît Canet
2014-08-23 0:59 ` Chris Friesen
2014-08-23 7:56 ` Benoît Canet
2014-08-25 15:12 ` Chris Friesen
2014-08-25 17:43 ` Chris Friesen
2015-08-27 16:37 ` Stefan Hajnoczi
2015-08-27 16:33 ` Stefan Hajnoczi
2014-08-25 21:50 ` Chris Friesen
2014-08-27 5:43 ` Chris Friesen
2015-05-14 13:42 ` Andrey Korolyov
2015-08-26 17:10 ` Andrey Korolyov
2015-08-26 23:31 ` Josh Durgin
2015-08-26 23:47 ` Andrey Korolyov
2015-08-27 0:56 ` Josh Durgin
2015-08-27 16:48 ` Stefan Hajnoczi
2015-08-27 17:05 ` Stefan Hajnoczi
2015-08-27 16:49 ` Stefan Hajnoczi
2015-08-28 0:31 ` Josh Durgin
2015-08-28 8:31 ` Andrey Korolyov
2014-07-21 19:47 ` Benoît Canet
2014-07-21 21:12 ` Chris Friesen
2014-07-21 22:04 ` Benoît Canet
2014-07-18 15:54 ` Andrey Korolyov
2014-07-18 16:26 ` Chris Friesen
2014-07-18 16:30 ` Andrey Korolyov
2014-07-18 16:46 ` Chris Friesen
[not found] <1000957815.25879188.1441820902018.JavaMail.zimbra@redhat.com>
2015-09-09 18:51 ` Jason Dillaman
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