Messages in this thread | | | From | Odin Ugedal <> | Date | Thu, 20 May 2021 16:11:52 +0200 | Subject | Re: [PATCH v5 2/3] sched/fair: Add cfs bandwidth burst statistics |
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I am a bit sceptical about both the nr_burst and burst_time as they are now.
As an example; a control group using "99.9%" of the quota each period and that is never throttled. Such group would with this patch with a burst of X still get nr_throttled = 0 (as before), but it would get a nr_burst and burst_time that will keep increasing.
I think there is a big difference between runtime moved/taken from cfs_b->runtime to cfs_rq->runtime_remaining and the actual runtime used in the period. Currently, cfs bw can only supply info the first one, and not the latter.
I think that if people see nr_burst increasing, that they think they _have_ to use cfs burst in order to avoid being throttled, even though that might not be the case. It is probably fine as is, as long as it is explicitly stated what the values mean and imply, and what they do not. I cannot see another way to calculate it as it is now, but maybe someone else has some thoughts.
Thanks Odin
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