On 08/24/2012 11:11 AM, Michael Wolf wrote: > On Fri, 2012-08-24 at 08:53 +0400, Glauber Costa wrote: >> On 08/24/2012 03:14 AM, Michael Wolf wrote: >>> This is an RFC regarding the reporting of stealtime. In the case of >>> where you have a system that is running with partial processors such as >>> KVM the user may see steal time being reported in accounting tools such >>> as top or vmstat. This can cause confusion for the end user. To >>> ease the confusion this patch set adds a sysctl interface to set the >>> cpu entitlement. This is the percentage of cpu that the guest system is >>> expected to receive. As long as the steal time is within its expected >>> range it will show up as 0 in /proc/stat. The user will then see in the >>> accounting tools that they are getting a full utilization of the cpu >>> resources assigned to them. >>> >> >> And how is such a knob not confusing? >> >> Steal time is pretty well defined in meaning and is shown in top for >> ages. I really don't see the point for this. > > Currently you can see the steal time but you have no way of knowing if > the cpu utilization you are seeing on the guest is the expected amount. > I decided on making it a knob because a guest could be migrated to > another system and it's entitlement could change because of hardware or > load differences. It could simply be a /proc file and report the > current entitlement if needed. As things are currently implemented I > don't see how someone knows if the guest is running as expected or > whether there is a problem. > Turning off steal time display won't get even close to displaying the information you want. What you probably want is a guest-visible way to say how many miliseconds you are expected to run each second. Right? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
