How can I get CPU user time and system time for each cpu on AIX.
I know I can get this value from cat /proc/stat on a linux machine, and from pstat_getprocessor() on an HP-UX machine. Is there a way to get this same metric on an AIX machine.
$ cat /proc/stat
...
cpu 23697394 7969 2744135 4505191649 2958605 190 17883 0 0
cpu0 12511394 4575 1520243 2251753159 1480624 137 10580 0 0
cpu1 11186000 3394 1223891 2253438490 1477980 53 7302 0 0
...
mpstat is providing these metrics, either parse its output or figure out how/where does it find them.
Related
I want to figure out how much memory a specific command uses but I'm not sure how to check for the peak memory of the command. Is there anything like the time([command]) usage but for memory?
Basically, I'm going to have to run an interactive queue using SLURM, then test a command for a program I need to use for a single sample, see how much memory was used, then submit a bunch of jobs using that info.
Yes, time is the program that monitors programs and shows the Maximum resident set size. Not to be confused with time Bash builtin that only shows real/user/sys times. On my Arch Linux you have to install time with pacman -S time, it's a separate package.
$ command time -v echo 1
1
Command being timed: "echo 1"
User time (seconds): 0.00
System time (seconds): 0.00
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 1968
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 90
Voluntary context switches: 1
Involuntary context switches: 1
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
Note:
$ type time
time is a shell keyword
$ time -V
bash: -V: command not found
real 0m0.002s
user 0m0.000s
sys 0m0.002s
$ command time -V
time (GNU Time) 1.9
$ /bin/time -V
time (GNU Time) 1.9
$ /usr/bin/time -V
time (GNU Time) 1.9
Is it possible to get this counter via procfs/sysfs? That is how many times CPU preempted any active task. Per process value is also OK.
Linux pve-index 4.15.18-5-pve #1 SMP PVE 4.15.18-24 (Thu, 13 Sep 2018 09:15:10 +0200) x86_64 GNU/Linux
If you mean non-voluntary context switches, then there is at least couple files under /proc:
# cat /proc/61115/status | grep ctxt_switches
voluntary_ctxt_switches: 6511
nonvoluntary_ctxt_switches: 143
# cat /proc/61115/sched
bash (61115, #threads: 1)
-------------------------------------------------------------------
...
nr_switches : 6594
nr_voluntary_switches : 6451
nr_involuntary_switches : 143
Just replace number 61115 with the wanted pid.
I am running a script that loads big files. I ran the same script in a single core OpenSuSe server and quad core PC. As expected in my PC it is much more faster than in the server. But, the script slows down the server and makes it impossible to do anything else.
My script is
for 100 iterations
Load saved data (about 10 mb)
time myscript (in PC)
real 0m52.564s
user 0m51.768s
sys 0m0.524s
time myscript (in server)
real 32m32.810s
user 4m37.677s
sys 12m51.524s
I wonder why "sys" is so high when i run the code in server. I used top command to check the memory and cpu usage.
It seems there is still free memory, so swapping is not the reason. % sy is so high, its probably the reason for the speed of server but I dont know what is causing % sy so high. The process that is using highest percent of CPU (99%) is "myscript". %wa is zero in the screenshot but sometimes it gets very high (50 %).
When the script is running, load average is greater than 1 but have never seen to be as high as 2.
I also checked my disc:
strt:~ # hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 16480 MB in 2.00 seconds = 8247.94 MB/sec
Timing buffered disk reads: 20 MB in 3.44 seconds = 5.81 MB/sec
john#strt:~> df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 245G 102G 131G 44% /
udev 4.0G 152K 4.0G 1% /dev
tmpfs 4.0G 76K 4.0G 1% /dev/shm
I have checked these things but I am still not sure what is the real problem in my server and how to fix it. Can anyone identify a probable reason for the slowness? What could be the solution?
Or is there anything else I should check?
Thanks!
You're getting a high sys activity because the load of the data you're doing takes system calls that happen in kernel. To resolve your slowness problems without upgrading the server might be possible. You can modify scheduling priority. See the man pages for nice and renice. See here and especially:
Niceness values range from -20 (the highest priority, lowest niceness) and 19 (the lowest priority, highest niceness).
$ ps -lp 941
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD
4 S 0 941 1 0 70 -10 - 1713 poll_s ? 00:00:00 sshd
$ nice -n 19 ./test.sh
My niceness value is 19
$ renice -n 10 -p 941
941 (process ID) old priority -10, new priority 10
I run a script on Ubuntu, and tested its time:
$ time ./merger
./merger 0.02s user 0.03s system 99% cpu 0.050 total
it spent less than 1 second.
but if I used cygwin:
$ time ./merger
real 3m22.407s
user 0m0.367s
sys 0m0.354s
It spent more than 3 minutes.
Why did this happen? What shall I do to increase the executing speed on cygwin?
As others have already mentioned, Cygwin's implementation of fork and process spawning on Windows in general are slow.
Using this fork() benchmark, I get following results:
rr-#cygwin:~$ ./test 1000
Forked, executed and destroyed 1000 processes in 5.660011 seconds.
rr-#arch:~$ ./test 1000
Forked, executed and destroyed 1000 processes in 0.142595 seconds.
rr-#debian:~$ ./test 1000
Forked, executed and destroyed 1000 processes in 1.141982 seconds.
Using time (for i in {1..10000};do cat /dev/null;done) to benchmark process spawning performance, I get following results:
rr-#work:~$ time (for i in {1..10000};do cat /dev/null;done)
(...) 19.11s user 38.13s system 87% cpu 1:05.48 total
rr-#arch:~$ time (for i in {1..10000};do cat /dev/null;done)
(...) 0.06s user 0.56s system 18% cpu 3.407 total
rr-#debian:~$ time (for i in {1..10000};do cat /dev/null;done)
(...) 0.51s user 4.98s system 21% cpu 25.354 total
Hardware specifications:
cygwin: Intel(R) Core(TM) i7-3770K CPU # 3.50GHz
arch: Intel(R) Core(TM) i7-4790K CPU # 4.00GHz
debian: Intel(R) Core(TM)2 Duo CPU T5270 # 1.40GHz
So as you see, no matter what you use, Cygwin will always operate worse. It loses hands down even to worse hardware (cygwin vs. debian in this benchmark, as per this comparison).
How could I get the CPU utilization with time info of a process in linux? Basically I want to let my application run overnight. At the same time, I would like to monitor the CPU utilization during the period the application is run.
I tried top | grep appName >& log, it does not seem to return me anything in the log. Could someone help me with this?
Thanks.
vmstat and iostat can both give you periodic information of this nature; I would suggest either setting up the number of times manually, or putting a single poll into a cron job, and then redirecting the output to a file:
vmstat 20 4230 >> cpu_log_file
This would give you a snapshot of usage every 20 seconds for 24 hours.
install sysstat package and run sar
nohup sar -o output.file 12 8 >/dev/null 2>&1 &
use the top or watch command
PID COMMAND %CPU TIME #TH #WQ #PORT #MREG RPRVT RSHRD RSIZE VPRVT VSIZE PGRP PPID STATE UID FAULTS COW MSGSENT MSGRECV SYSBSD SYSMACH CSW PAGEINS USER
10764 top 8.4 00:01.04 1/1 0 24 33 2000K 244K 2576K 17M 2378M 10764 10719 running 0 9908+ 54 564790+ 282365+ 3381+ 283412+ 838+ 27 root
10763 taskgated 0.0 00:00.00 2 0 25 27 432K 244K 1004K 27M 2387M 10763 1 sleeping 0 376 60 140 60 160 109 11 0 root
Write a program that invokes your process and then calls getrusage(2) and reports statistics for its children.
You can monitor the time used by your program with top while it is running.
Alternatively, you can launch your application with the time command, which will print the total amount of CPU time used by your program at the end of its execution. Just type time ./my_app instead of just ./my_app
For more info, man 1 time