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From: Alberto Garcia <berto@igalia.com>
To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-devel@nongnu.org, ngu@redhat.com
Subject: Re: [Qemu-devel] Confusing I/O throttling behavior with burst_length > 1 and max < avg
Date: Tue, 26 Jul 2016 14:38:43 +0200	[thread overview]
Message-ID: <20160726123843.GA10992@igalia.com> (raw)
In-Reply-To: <20160714121819.GR15476@stefanha-x1.localdomain>

On Thu, Jul 14, 2016 at 01:18:19PM +0100, Stefan Hajnoczi wrote:

> The following throttling behavior was observed with bps=512000
> bps_max=51200 throttling.bps-total-max-length=2:
> 
>   READ: io=512KB, aggrb=50KB/s, minb=50KB/s, maxb=50KB/s, mint=10061msec, maxt=10061msec
> 
> If bps-total-max-length=1 then the result is different:
> 
>   READ: io=5056KB, aggrb=505KB/s, minb=505KB/s, maxb=505KB/s, mint=10006msec, maxt=10006msec
> 
> The burst limits guest bps instead of adding on top of it when
> burst_length > 1.

Thanks Stefan,

I think we should forbid that kind of setup altogether. I wrote a few
more details in the bug report:

> https://bugzilla.redhat.com/show_bug.cgi?id=1355665

I can write the patch.

Berto

  reply	other threads:[~2016-07-26 12:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-14 12:18 [Qemu-devel] Confusing I/O throttling behavior with burst_length > 1 and max < avg Stefan Hajnoczi
2016-07-26 12:38 ` Alberto Garcia [this message]
  -- strict thread matches above, loose matches on Subject: below --
2016-07-14 12:18 Stefan Hajnoczi

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