Messages in this thread |  | | Date | Mon, 18 Feb 2013 22:11:04 -0300 | From | Marcelo Tosatti <> | Subject | Re: [PATCH 0/4] Alter steal-time reporting in the guest |
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On Mon, Feb 18, 2013 at 05:43:47PM +0100, Frederic Weisbecker wrote: > 2013/2/5 Michael Wolf <mjw@linux.vnet.ibm.com>: > > In the case of where you have a system that is running in a > > capped or overcommitted environment the user may see steal time > > being reported in accounting tools such as top or vmstat. This can > > cause confusion for the end user. > > Sorry, I'm no expert in this area. But I don't really understand what > is confusing for the end user here.
I suppose that what is wanted is to subtract stolen time due to 'known reasons' from steal time reporting. 'Known reasons' being, for example, hard caps. So a vcpu executing instructions with no halt, but limited to 80% of available bandwidth, would not have 20% of stolen time reported.
But yes, a description of the scenario that is being dealt with, with details, is important.
> > To ease the confusion this patch set > > adds the idea of consigned (expected steal) time. The host will separate > > the consigned time from the steal time. Tthe steal time will only be altered > > if hard limits (cfs bandwidth control) is used. The period and the quota used > > to separate the consigned time (expected steal) from the steal time are taken > > from the cfs bandwidth control settings. Any other steal time accruing during > > that period will show as the traditional steal time. > > I'm also a bit confused here. steal time will then only account the > cpu time lost due to quotas from cfs bandwidth control? Also what do > you exactly mean by "expected steal time"? Is it steal time due to > overcommitting minus scheduler quotas? > > Thanks.
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