Only measure necessary counters in Marker API

[GoogleCodeExporter]

Problem:

At the moment the Marker API measures all Counters, because it does not know 
which counters are part of the group. While this is OK for a small number of 
overall counters it adds a lot of overhead on architectures with many counters 
(as Intel EX type Xeons or SandyBridge)

Solution:

Implement a solution so that the Marker API only measures counters which are 
part of the current group.

This is best done using a environment variable. The marker API later checks for 
bits to only read out needed counters.

Original issue reported on code.google.com by jan.trei...@gmail.com on 3 Dec 2012 at 9:30

[GoogleCodeExporter]

Original comment by jan.trei...@gmail.com on 8 May 2013 at 8:24

• Added labels: Release-3.1

[GoogleCodeExporter]

Original comment by jan.trei...@gmail.com on 13 Sep 2013 at 7:16

• Changed state: Started

[GoogleCodeExporter]

This issue was closed by revision 16e3f9120ef8.

Original comment by jan.trei...@gmail.com on 14 Nov 2013 at 12:52

• Changed state: Fixed