perf: Add support for hardware breakpoint address masks

[Kim Naru]

The following patchset adds address masks to existing perf hardware
breakpoint mechanism to allow trapping on an address range (currently
only single address) on supported architectures.

perf uapi is updated, x86 AMD implementation (for AMD Family 16h and
beyond) is provided, and perf tool has been extended to do:

  $ perf stat -e mem:0x1000:w:0xf a.out
                              ^^^
                              "don't care" bit mask

  which will count writes to [0x1000 ~ 0x1010)

This patch is upstream but not accepted yet:

https://lkml.org/lkml/2012/12/12/261

[Leann Ogasawara (leannogasawara)]

Is there any information if these patches have hit a maintainer's tree and if they will land in the v3.9 merge window? We'd prefer to pick these up from a more official upstream repo if possible. Thanks.

[Kim Naru (kim-naru)]

This patch will probably not get into Linux 3.9. We will try to get it into 3.10.

[James M. Leddy (jm-leddy)]

Hi Kim,

We're going to use 3.11 for saucy, is the patch in 3.11?

[Kim Naru (kim-naru)]

No it is not.

[James M. Leddy (jm-leddy)]

This looks to be on hold because I haven't seen anything since v2 of this patch:

http://thread.gmane.org/gmane.linux.kernel/1479542

Correct me if there is something more current.

[Kim Naru (kim-naru)]

The code has not been acked by the maintainer.

[James M. Leddy (jm-leddy)]

Hi Kim,

It seems the maintainer had a few concerns that need to be addressed, probably in a v3 of this patchset. Is Jacob planning on doing a v3?

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1117548

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[James M. Leddy (jm-leddy)]

Confirmed with Kim that Jacob is still working on this and is planning on resubmitting.

[Kim Naru (kim-naru)]

Appears this will go into Linux 3.15.