aDriv4 - MANAGER

Edit File: runqlen_example.txt

Demonstrations of runqlen, the Linux BPF/bpftrace version. This tool samples the length of the CPU scheduler run queues, showing these sampled lengths as a histogram. This can be used to characterize demand for CPU resources. For example: # ./runqlen.bt Attaching 2 probes... Sampling run queue length at 99 Hertz... Hit Ctrl-C to end. ^C @runqlen: [0, 1) 1967 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [1, 2) 0 | | [2, 3) 0 | | [3, 4) 306 |@@@@@@@@ | This output shows that the run queue length was usually zero, except for some samples where it was 3. This was caused by binding 4 CPU bound threads to a single CPUs. There is another version of this tool in bcc: https://github.com/iovisor/bcc The bcc version provides options to customize the output.