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https://issues.apache.org/jira/browse/MESOS-4595?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15132546#comment-15132546
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Bartek Plotka edited comment on MESOS-4595 at 2/9/16 12:36 PM:
---------------------------------------------------------------
Patch: https://reviews.apache.org/r/43358/
was (Author: bartek plotka):
I have created a short sample patch for reference:
https://reviews.apache.org/r/43141/diff/1#index_header
Hope, it'll help to understand this issue.
> Add support for newest pre-defined Perf events to PerfEventIsolator
> -------------------------------------------------------------------
>
> Key: MESOS-4595
> URL: https://issues.apache.org/jira/browse/MESOS-4595
> Project: Mesos
> Issue Type: Task
> Components: isolation
> Reporter: Bartek Plotka
> Assignee: Bartek Plotka
> Priority: Minor
>
> Currently, Perf Event Isolator is able to monitor all (specified in
> {{--perf_events=...}}) Perf Events, but it can map only part of them in
> {{ResourceUsage.proto}} (to be more exact in [PerfStatistics.proto |
> https://github.com/apache/mesos/blob/master/include/mesos/mesos.proto#L862])
> Since the last time {{PerfStatistics.proto}} was updated, list of supported
> events expanded much and is growing constantly. I have created some
> comparison table:
> || Events type || Num of matched events in PerfStatistics vs perf 4.3.3 ||
> perf 4.3.3 events ||
> | HW events | 8 | 8 |
> | SW events | 9 | 10 |
> | HW cache event | 20 | 20 |
> | *Kernel PMU events* | *0* | *37* |
> | Tracepoint events | 0 | billion (: |
> For advance analysis (e.g during Oversubscription in QoS Controller) having
> support for additional events is crucial. For instance in
> [Serenity|https://github.com/mesosphere/serenity] we based some of our
> revocation algorithms on the new [CMT|
> https://01.org/packet-processing/cache-monitoring-technology-memory-bandwidth-monitoring-cache-allocation-technology-code-and-data]
> feature which gives additional, useful event called {{llc_occupancy}}.
> I think we all agree that it would be great to support more (or even all)
> perf events in {{Mesos PerfEventIsolator}} (:
> ----
> Let's start a discussion over the approach. Within this task we have three
> issues:
> # What events do we want to support in Mesos?
> ## all?
> ## only add Kernel PMU Events?
> ---
> I don't have a strong opinion on that, since i have never used {{Tracepoint
> events}}. We currently need PMU events.
> # How to add new (or modify existing) events in {{mesos.proto}}?
> We can distinguish here 3 approaches:
> *# Add new events statically in {{PerfStatistics.proto}} as separate optional
> fields. (like it is currently)
> *# Instead of optional fields in {{PerfStatistics.proto}} message we could
> have a {{key-value}} map (something like {{labels}} in other messages) and
> feed it dynamically in {{PerfEventIsolator}}
> *# We could mix above approaches and just add mentioned map to existing
> {{PerfStatistics.proto}} for additional events (:
> ---
> IMO: Approaches 1) is somehow explicit - users can view what events to expect
> (although they are parsed in a different manner e.g {{"-"}} to {{"_"}}), but
> we would end with a looong message and a lot of copy-paste work. And we have
> to maintain that!
> Approach 2 & 3 are more elastic, and we don't have problem mentioned in the
> issue below (: And we *always* support *all* perf events in all kernel
> versions (:
> IMO approaches 2 & 3 are the best.
> # How to support different naming format? For instance
> {{intel_cqm/llc_occupancy/}} with {{"/"}} in name or
> {{migrate:mm_migrate_pages}} with {{":"}}. I don't think it is possible to
> have these as the field names in {{.proto}} syntax
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