am using the Linux Perf tool to monitor certain events for my benchmarking runs. In the event list argument -e, I added cycles-t and cycles-ct since I want to capture them. But both of them always return 0 when I run perf.I am using following command for example:perf stat -e cycles-ct dd if=/dev/zero of=/dev/numm count=10000and this is the output10000+0 records in10000+0 records out5120000 bytes (5.1 MB) copied, 0.0318331 s, 161 MB/s Performance counter stats for 'dd if=/dev/zero of=/dev/numm count=10000':        31,957,327      cycles-ct                                 0      cpu/cycles-ct/                                                     0.035254063 seconds time elapsedAny idea on this? I need to get cpu/cycles-ct values. (I am on Fedora 20. Tried updating the perf utility, it did not resolve my problem.)Also if I run this commandperf stat -T -a sleep 1I get the output as follows:Performance counter stats for 'system wide':       8022.927913      task-clock (msec)         #    8.011 CPUs utilized                   104842699      instructions              #    0.87  insns per cycle         [100.00%]         120099715      cycles                    #    0.015 GHz                     [100.00%]            162615      cpu/cycles-t/             #    0.14% transactional cycles    [100.00%]               773      cpu/tx-start/             #      210 cycles / transaction    [100.00%]                 0      cpu/el-start/             #    0.000 K/sec                   [100.00%]            111864      cpu/cycles-ct/            #    0.04% aborted cycles                1.001474976 seconds time elapsed
Perf Tool Linux - Not counting cycles-t and cycles-ct
fedora;perf event;perf