[Feature] Enable Intel® Cache Monitoring Technology

[Yingying Zhao]

Intel® Cache Monitoring Technology is a new CPU feature found in the Haswell Server family. It provides a mechanism for monitoring cache occupancy usage of tasks running on the CPUs.

Prior to Haswell, there was no mechanism to tell how much of the cache was in use by a task/process, just that a process either caused a cache miss or a cache hit.

This feature can be useful for customers who want to better manage their processing resources. If a user can identify processes that are large consumers of the cache, those processes can either be moved to another system, or the process itself can be investigated for optimizations.

Upstream status:
Kernel:target 4.1
Xen: target 4.5 (Done)

Target Ubuntu Release: Ubuntu 15.04

[Leann Ogasawara (leannogasawara)]

Hi Yingying,

Do you have references to any upstream commits for this so we can verify if we've picked these up already or not? Thanks.

[Yingying Zhao (yingying-zhao)]

Patches for this support have now been posted to LKML,
http://marc.info/?l=linux-kernel&m=141156746730336

Let's retarget this feature for 15.04.

[Yingying Zhao (yingying-zhao)]

For the Xen side, the latest update is:

Still in pushing the version 15 of this patchset. While most comments related to CQM itself have been accepted by maintainer. Other comments are related to XEN common code changes, like generic resource access framework and multicall batch processing mechanism which CQM is built on top of.
The CQM in XEN is independent with guest OS.

[Yingying Zhao (yingying-zhao)]

The Xen patches are already included in Xen 4.5.

I updated the title to "Intel® Cache Monitoring Technology" which is the official name and I also change the kernel target to 3.19.

Intel posted the v3 patch here:
http://marc.info/?l=linux-kernel&m=141527661802102

[XiongZhang (xiong-y-zhang)]

For kernel part, sitting in a tip branch (perf/x86) and will be part of kernel 4.1

[Leann Ogasawara (leannogasawara)]

Per discussion between Canonical and Intel, retarget to 15.10.

[XiongZhang (xiong-y-zhang)]

4.1 kernel fulfill this:
39bed6cbb842d8edf5a26b01122b391d36775b5e
eacd3ecc34472ce3751eedfc94e44c7cc6eb6305
79dff51e900fd26a073be8b23acfbd8c15edb181
cbc82b17263877ea5d21e84c58ce03f0292458a1
4afbb24ce5e723c8a093a6674a3c33062175078a
35298e554c74b7849875e3676ba8eaf833c7b917
bfe1fcd2688f557a6b6a88f59ea7619228728bd7
bff671dba7981195a644a5dc210d65de8ae2d251
59bf7fd45c90a8fde22a7717b5413e4ed9666c32

[Leann Ogasawara (leannogasawara)]

Marking this Fix Released for 15.10