Listing down some command line tools I have found useful for monitoring/experimenting for later reference.
CPU and memory utilization
Use top(1) to see the CPU and memory utilization of the threads in a process
top -H -p <pid>
cpusets
Use https://github.com/SUSE/cpuset to easily try out cpusets (refer https://github.com/SUSE/cpuset/blob/master/INSTALL for building and installing from source)
e.g.
Cores 1,2, and 3 in user group
cset shield -c 1-3
Move the specified process and all its threads to user group
cset shield --shield --pid=<pid> --threads
CPU affinity
e.g.
Set CPU affinity of all threads of the specified process to cores 0 and 1
taskset -a -pc 0,1 <pid>
Scheduling policies, priorities
See sched(7) for scheduling details.
Linux scheduler makes decisions based on scheduling policy and priority of threads.
Use chrt(1) to manipulate policy/priority of a process.
e.g.
Set all threads of the specified process to have policy SCHED_RR and priority 30
chrt -a -p -r 30 <pid>
e.g.
Show minimum and maximum valid priorities
$ chrt -m SCHED_OTHER min/max priority : 0/0 SCHED_FIFO min/max priority : 1/99 SCHED_RR min/max priority : 1/99 SCHED_BATCH min/max priority : 0/0 SCHED_IDLE min/max priority : 0/0 SCHED_DEADLINE min/max priority : 0/0
Change a thread's policy to fifo and priority to max
$ chrt -p -f 99 4296
Verify it's set properly
$ chrt -p 4296
pid 4296's current scheduling policy: SCHED_FIFO
pid 4296's current scheduling priority: 99
Naming pthreads
Not related to command line, but very useful for debugging/monitoring purposes, for example
top -H -p <pid>
will show us the thread name.
You can use
prctl(2) with option PR_SET_NAME: this will set the name of the calling thread