Question: Something is pegging my CPU. How do I pinpoint it with real-time refresh?
Try:top -b -n 1 -o %CPU | head -20
Info: Running top in batch mode (-b -n 1) executes a single non-interactive snapshot, while -o %CPU dynamically sorts processes by CPU utilization for quick diagnostics and scripting.
Examples:
$ top -b -n 1 -o %MEM | head # Snapshot sorted by memory consumption
$ top -b -n 1 -u mysql # Filter snapshot processes by specific user
$ top -b -n 1 -p 3456,2134 # Inspect specific target Process IDs (PIDs)
Note: Pay attention to wa (I/O wait; high values indicate disk bottlenecks) and st (stolen CPU; high values indicate hypervisor contention). Multi-threaded processes can exceed 100% CPU.
LinuxTeck.com
linuxteck:~$ top -b -n 1 -o %CPU | head -20
top - 09:34:12 up 23 days, 4:12, 2 users, load average: 2.45, 1.89, 1.67
Tasks: 234 total, 3 running, 231 sleeping, 0 stopped, 0 zombie
%Cpu(s): 45.2 us, 8.3 sy, 0.0 ni, 44.5 id, 1.5 wa, 0.0 hi, 0.5 si, 0.0 st
MiB Mem : 15987.4 total, 2345.6 free, 8901.2 used, 4740.6 buff/cache
MiB Swap: 2048.0 total, 2048.0 free, 0.0 used. 6543.2 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3456 mysql 20 0 4823456 2345m 12456 S 87.3 14.7 234:12.34 mysqld
2134 www-data 20 0 456872 87m 23456 R 45.2 0.5 89:23.45 nginx
5678 linuxteck 20 0 1876543 876m 34567 S 12.3 5.4 123:45.67 chrome
4321 root 20 0 234567 34m 4567 S 3.4 0.2 5:12.34 systemd-journald
1234 nginx 20 0 567890 45m 6789 R 2.1 0.3 8:56.78 nginx
linuxteck:~$
John Britto Founder & Chief-Editor @LinuxTeck. A Computer Geek and Linux Intellectual having more than 20+ years of experience in Linux and Open Source technologies.
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