Messages in this thread | | | Date | Wed, 8 Feb 2017 11:11:35 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 00/12] Cqm2: Intel Cache quality monitoring fixes |
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On Fri, Jan 20, 2017 at 12:11:53PM -0800, David Carrillo-Cisneros wrote: > Implementation ideas: > > First idea is to expose one monitoring file per resource in a CTRLGRP, > so the list of CTRLGRP's files would be: schemata, tasks, cpus, > monitor_l3_0, monitor_l3_1, ... > > the monitor_<resource_id> file descriptor is passed to perf_event_open > in the way cgroup file descriptors are passed now. All events to the > same (CTRLGRP,resource_id) share RMID. > > The RMID allocation part can either be handled by RDT Allocation or by > the RDT Monitoring PMU. Either ways, the existence of PMU's > perf_events allocates/releases the RMID.
So I've had complaints about exactly that behaviour. Someone wanted RMIDs assigned (and start measuring) the moment the grouping got created/tasks started running etc..
So I think the design should also explicitly state how this is supposed to be handled and not left as an implementation detail.
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