My system is Linux CentOS 3.6, Parallel Studio XE 2013
Compiling for MIC KMP_AFFINITY=compact and KMP_AFFINITY=scatter works as expected (I have Xeon Phi). Threads are pinned properly.
Compiling for host processor E5-2620 V2 things are different.
KMP_AFFINITY=scatter, with OMP_NUM_THREADS=12 will at times distribute to all 12 hardware threads but not in the expected order.
*** most of the time, different OpenMP threads get assigned to the same hardware thread.
On subsequent runs the thread placement is arbitrary, and occasionally some different sw threads get assigned to the same hw thread.
It is behaving as if pinning were not occurring.
Using KMP=compact, with OMP_NUM_THREADS=12, most of the time, if not always (don't trust it), will assign the even/odd hw threads of each core to even/odd pairs of OpenMP threads, however the evenness and oddness of which changes
0, 1 (note swap of even/odd her)
6, 6 (note even/even)
7, 7 (note odd/odd)
Note, I have performed "sudo yum install schedutils" (it says already installed)
Any hints to fix the affinity issue on host processor under CentOS 3.6 would be appreciated.