Performance Counter Problem Between HW and simx in Tutorial Assignments

[owlxiao]

Hello, I'm currently working on the tutorial assignments, and after completing 2, I have a question.I noticed an issue with the performance counters in both simx and hw.

HW achieves higher efficiency than simx. In the relevant data, the values for total_active_threads_per_core show a significant discrepancy. I ran multiple workloads, and the results consistently showed the same pattern. Test repository commit link1 and link2.

The test command used was:

./ci/blackbox.sh --cores=4 --app=vecadd --perf=3 --driver=simx --args="-n16"

hw results:

Verify result
PASSED!
PERF: core0: Warp Efficiency=81% total_active_threads_per_core=4910 total_issued_warps_per_core=1503
PERF: core0: instrs=4903, cycles=27851, IPC=0.176044
PERF: core1: Warp Efficiency=76% total_active_threads_per_core=3247 total_issued_warps_per_core=1055
PERF: core1: instrs=3240, cycles=24140, IPC=0.134217
PERF: core2: Warp Efficiency=76% total_active_threads_per_core=3247 total_issued_warps_per_core=1055
PERF: core2: instrs=3240, cycles=24141, IPC=0.134212
PERF: core3: Warp Efficiency=76% total_active_threads_per_core=3247 total_issued_warps_per_core=1055
PERF: core3: instrs=3240, cycles=24142, IPC=0.134206
PERF: Warp Efficiency=78%
PERF: instrs=14623, cycles=27851, IPC=0.525044

simx result:

Verify result
PASSED!
PERF: core0: Warp Efficiency=25% total_active_threads_per_core=1503 total_issued_warps_per_core=1501
PERF: core0: instrs=4900, cycles=27781, IPC=0.176380
PERF: core1: Warp Efficiency=25% total_active_threads_per_core=1055 total_issued_warps_per_core=1053
PERF: core1: instrs=3237, cycles=24237, IPC=0.133556
PERF: core2: Warp Efficiency=25% total_active_threads_per_core=1055 total_issued_warps_per_core=1053
PERF: core2: instrs=3237, cycles=24238, IPC=0.133551
PERF: core3: Warp Efficiency=25% total_active_threads_per_core=1055 total_issued_warps_per_core=1053
PERF: core3: instrs=3237, cycles=24239, IPC=0.133545
PERF: Warp Efficiency=25%
PERF: instrs=14611, cycles=27781, IPC=0.525935