Re: [PATCH 0/4] x86: Add Cache QoS Monitoring (CQM) support
From: Peter Zijlstra <hidden>
Date: 2014-01-06 11:08:26
Also in:
lkml
From: Peter Zijlstra <hidden>
Date: 2014-01-06 11:08:26
Also in:
lkml
On Fri, Jan 03, 2014 at 12:34:41PM -0800, Peter P Waskiewicz Jr wrote:
The CPU features themselves are relatively straight-forward, but the presentation of the data is less straight-forward. Since this tracks cache usage and occupancy per process (by swapping Resource Monitor IDs, or RMIDs, when processes are rescheduled), perf would not be a good fit for this data, which does not report on a per-process level. Therefore, a new cgroup subsystem, cacheqos, has been added. This operates very similarly to the cpu and cpuacct cgroup subsystems, where tasks can be grouped into sub-leaves of the root-level cgroup.
This doesn't make any sense.. From a quick SDM read you can do pretty much whatever with those RMIDs. If you allocate a RMID per task (thread in userspace) you can actually measure things on a task basis. From then on you can use perf-cgroup to group whatever tasks you want. So please be more explicit in why you think this doesn't fit into perf.