How do I measure separate CPU core usage for a process

Question

Is there any way to measure a specific process CPU usage by cores   I know top is good for measuring the whole system s CPU usage by cores and taskset can provide information about which CPU core is allowed for the process to run on   But how do I measure a specific process  CPU usage by CPU cores

User · Answer

htop gives a nice overview of individual core usage

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you can use ps  e g  having python process with two busy threads on dual core CPU     ps -p 29492 -L -o pid tid psr pcpu   PID   TID PSR  CPU 29492 29492   1  0 0 29492 29493   1 48 7 29492 29494   1 51 9    PSR is CPU id the thread is currently assigned to   you see that the threads are running on the same cpu core  because of GIL   running the same python script in jython  we see  that the script is utilizing both cores  and there are many other service or whatever threads  which are almost idle      ps -p 28671 -L -o pid tid psr pcpu   PID   TID PSR  CPU 28671 28671   1  0 0 28671 28672   0  4 4 28671 28673   0  0 6 28671 28674   0  0 5 28671 28675   0  2 3 28671 28676   0  0 0 28671 28677   1  0 0 28671 28678   1  0 0 28671 28679   0  4 6 28671 28680   0  4 4 28671 28681   1  0 0 28671 28682   1  0 0 28671 28721   1  0 0 28671 28729   0 88 6 28671 28730   1 88 5   you can process the output and calculate the total CPU for each CPU core   Unfortunately  this approach does not seem to be 100  reliable  sometimes i see that in the first case  the two working threads are reported to be separated to each CPU core  or in the latter case  the two threads are reported to be on the same core

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You can use    mpstat -P ALL 1   It shows how much each core is busy and it updates automatically each second  The output would be something like this  on a quad-core processor    10 54 41 PM  CPU     usr    nice     sys  iowait     irq    soft   steal   guest    idle 10 54 42 PM  all    8 20    0 12    0 75    0 00    0 00    0 00    0 00    0 00   90 93 10 54 42 PM    0   24 00    0 00    2 00    0 00    0 00    0 00    0 00    0 00   74 00 10 54 42 PM    1   22 00    0 00    2 00    0 00    0 00    0 00    0 00    0 00   76 00 10 54 42 PM    2    2 02    1 01    0 00    0 00    0 00    0 00    0 00    0 00   96 97 10 54 42 PM    3    2 00    0 00    0 00    0 00    0 00    0 00    0 00    0 00   98 00 10 54 42 PM    4   14 15    0 00    1 89    0 00    0 00    0 00    0 00    0 00   83 96 10 54 42 PM    5    1 00    0 00    0 00    0 00    0 00    0 00    0 00    0 00   99 00 10 54 42 PM    6    0 00    0 00    0 00    0 00    0 00    0 00    0 00    0 00  100 00 10 54 42 PM    7    0 00    0 00    0 00    0 00    0 00    0 00    0 00    0 00  100 00   This command doesn t answer original question though i e  it does not show CPU core usage for a specific process

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I had just this problem and I found a similar answer here   The method is to set top the way you want it and then press W  capital W   This saves top s current layout to a configuration file in  HOME  toprc  Although this might not work if you want to run multiple top s with different configurations   So via what I consider a work around you can write to different config files   use different config files by doing one of the following      1  Rename the binary    ln -s  usr bin top top2     top2   Now  top2rc is going to be written to your  HOME  2  Set  HOME to some alternative path  since it will write its config file to the  HOME  binary-name rc file  HOME    top   Now  toprc is going to be written to the current folder   Via use of other peoples comments to add the various usage accounting in top you can create a batch output for that information and latter coalesces the information via a script   Maybe not quite as simple as you script but I found top to provide me ALL processes so that later I can recap and capture a state during a long run that I might have missed otherwise  unexplained sudden CPU usage due to stray processes

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dstat -C 0 1 2 3    Will also give you the CPU usage of first 4 cores  Of course  if you have 32 cores then this command gets a little bit longer but useful if you only interested in few cores    For example  if you only interested in core 3 and 7 then you could do   dstat -C 3 7

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The ps solution was nearly what I needed and with some bash thrown in does exactly what the original question asked for  to see per-core usage of specific processes  This shows per-core usage of multi-threaded processes too   Use like  cpustat  pgrep processname   pgrep otherprocessname          bin bash  pids    while         0    do         pids     pids        1           shift done  if   -z    pids 0       then         echo  Usage   0  lt pid1 gt   pid2               exit 1 fi  for pid in    pids       do         if     -e  proc  pid    then                 echo  Error  pid  pid doesn t exist                  exit 1         fi done  while   true    do         echo -e   033 H 033 J          for pid in    pids       do                 ps -p  pid -L -o pid tid psr pcpu comm          done         sleep 1 done   Note  These stats are based on process lifetime  not the last X seconds  so you ll need to restart your process to reset the counter

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I thought perf stat is what you need    It shows a specific usage of a process when you specify a --cpu list option  Here is an example of monitoring cpu usage of building a project using perf stat --cpu 0-7 --no-aggr -- make all -j command  The output is   CPU0         119254 719293 task-clock  msec               1 000 CPUs utilized             100 00   CPU1         119254 724776 task-clock  msec               1 000 CPUs utilized             100 00   CPU2         119254 724179 task-clock  msec               1 000 CPUs utilized             100 00   CPU3         119254 720833 task-clock  msec               1 000 CPUs utilized             100 00   CPU4         119254 714109 task-clock  msec               1 000 CPUs utilized             100 00   CPU5         119254 727721 task-clock  msec               1 000 CPUs utilized             100 00   CPU6         119254 723447 task-clock  msec               1 000 CPUs utilized             100 00   CPU7         119254 722418 task-clock  msec               1 000 CPUs utilized             100 00   CPU0                 8 108 context-switches               0 068 K sec                     100 00   CPU1                26 494 context-switches                                               100 00   CPU2                10 193 context-switches                                               100 00   CPU3                12 298 context-switches                                               100 00   CPU4                16 179 context-switches                                               100 00   CPU5                57 389 context-switches                                               100 00   CPU6                 8 485 context-switches                                               100 00   CPU7                10 845 context-switches                                               100 00   CPU0                   167 cpu-migrations                 0 001 K sec                     100 00   CPU1                    80 cpu-migrations                                                 100 00   CPU2                   165 cpu-migrations                                                 100 00   CPU3                   139 cpu-migrations                                                 100 00   CPU4                   136 cpu-migrations                                                 100 00   CPU5                   175 cpu-migrations                                                 100 00   CPU6                   256 cpu-migrations                                                 100 00   CPU7                   195 cpu-migrations                                                 100 00     The left column is the specific CPU index and the right most column is the usage of the CPU  If you don t specify the --no-aggr option  the result will aggregated together  The --pid pid option will help if you want to monitor a running process    Try -a --per-core or -a perf-socket too  which will present more classified information   More about usage of perf stat can be seen in this tutorial  perf cpu statistic  also perf help stat will help on the meaning of the options

User · Answer

You can still do this in top   While top is running  press  1  on your keyboard  it will then show CPU usage per core   Limit the processes shown by having that specific process run under a specific user account and use Type  u  to limit to that user

[linux] How do I measure separate CPU core usage for a process?

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