strace, ltrace, iotop, iostat (sysstat)
Run 60 sec. strace, sorted by CPU time percent:
(export PID=27852; timeout 60 strace -fc -S time -o /tmp/$PID.`date '+%Y%m%d_%H%M'`.strace -p $PID)
cat /tmp/27852.20201124_1651.strace
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
33.12 0.201717 7 28828 write
31.33 0.190796 63599 3 unlink
28.98 0.176509 12 15252 225 read
6.56 0.039973 13324 3 munmap
0.00 0.000023 0 1161 464 stat
0.00 0.000020 0 464 lseek
0.00 0.000000 0 7 open
0.00 0.000000 0 7 close
0.00 0.000000 0 9 fstat
0.00 0.000000 0 906 poll
0.00 0.000000 0 3 mmap
0.00 0.000000 0 243 11 ioctl
0.00 0.000000 0 6 select
0.00 0.000000 0 2 getdents
0.00 0.000000 0 2 rename
0.00 0.000000 0 1 getrandom
------ ----------- ----------- --------- --------- ----------------
100.00 0.609038 46897 700 total
Bash