upgautam@amd:~$ uptime
20:09:14 up 1 day, 9:38, 1 user, load average: 0.18, 0.33, 0.31
It tells the load average is 0.18 for 1 minutes, 0.33 for 5 minutes, and 0.31 for 10 minutes. 0.33 means less than 1 process is running in last 5 minutes.
We can use stress command to increase these load average values.
upgautam@amd:~$ stress --cpu 64
stress: info: [156850] dispatching hogs: 64 cpu, 0 io, 0 vm, 0 hdd
This will saturate all 32 CPU (check using nproc). We can also test this using System Monitor GUI tool.
These are the uptime chronological outputs after stress command executed.
upgautam@amd:~$ uptime
20:11:51 up 1 day, 9:41, 1 user, load average: 10.35, 2.60, 1.07
upgautam@amd:~$ uptime
20:11:53 up 1 day, 9:41, 1 user, load average: 14.72, 3.64, 1.41
upgautam@amd:~$ uptime
20:11:55 up 1 day, 9:41, 1 user, load average: 14.72, 3.64, 1.41
upgautam@amd:~$ uptime
20:11:58 up 1 day, 9:41, 1 user, load average: 14.72, 3.64, 1.41
upgautam@amd:~$ uptime
20:12:07 up 1 day, 9:41, 1 user, load average: 22.53, 5.67, 2.10
upgautam@amd:~$ uptime
20:12:17 up 1 day, 9:41, 1 user, load average: 29.06, 7.63, 2.77
upgautam@amd:~$ uptime
20:12:19 up 1 day, 9:41, 1 user, load average: 32.02, 8.60, 3.11
upgautam@amd:~$ uptime
20:12:22 up 1 day, 9:41, 1 user, load average: 32.02, 8.60, 3.11
upgautam@amd:~$ uptime
20:12:24 up 1 day, 9:41, 1 user, load average: 34.82, 9.57, 3.46
upgautam@amd:~$ uptime
20:12:30 up 1 day, 9:41, 1 user, load average: 37.23, 10.49, 3.79
upgautam@amd:~$ uptime
20:12:32 up 1 day, 9:41, 1 user, load average: 37.23, 10.49, 3.79
upgautam@amd:~$ uptime
20:12:34 up 1 day, 9:41, 1 user, load average: 39.46, 11.39, 4.12
upgautam@amd:~$ uptime
20:12:35 up 1 day, 9:41, 1 user, load average: 39.46, 11.39, 4.12
upgautam@amd:~$ uptime
20:12:37 up 1 day, 9:42, 1 user, load average: 39.46, 11.39, 4.12
upgautam@amd:~$ uptime
20:13:16 up 1 day, 9:42, 1 user, load average: 52.55, 18.27, 6.74
upgautam@amd:~$ uptime
20:13:35 up 1 day, 9:42, 1 user, load average: 56.27, 21.35, 8.00
upgautam@amd:~$ uptime
20:13:55 up 1 day, 9:43, 1 user, load average: 58.75, 24.18, 9.21
upgautam@amd:~$ uptime
20:15:25 up 1 day, 9:44, 1 user, load average: 63.68, 34.80, 14.37
upgautam@amd:~$ uptime
20:15:39 up 1 day, 9:45, 1 user, load average: 63.75, 36.23, 15.16
upgautam@amd:~$ uptime
20:16:12 up 1 day, 9:45, 1 user, load average: 64.04, 38.93, 16.73
upgautam@amd:~$ uptime
20:16:45 up 1 day, 9:46, 1 user, load average: 64.46, 41.81, 18.52
All values converse around 64, which is the total number of threads (2 times the total number of cores). When these numbers are higher than the number of cores, it means processes are competing for resources.
This displays the snapshot of system.
upgautam@amd:~$ stress --cpu 64
stress: info: [156850] dispatching hogs: 64 cpu, 0 io, 0 vm, 0 hdd
now, we can check using top
upgautam@amd:~$ top
top - 21:16:45 up 1 day, 10:46, 1 user, load average: 64.64, 59.63, 50.94
Tasks: 658 total, 65 running, 588 sleeping, 4 stopped, 1 zombie
%Cpu(s): 99.5 us, 0.5 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 128541.6 total, 95745.2 free, 25684.1 used, 8468.9 buff/cache
MiB Swap: 94670.0 total, 94670.0 free, 0.0 used. 102857.5 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
182561 upgautam 20 0 3624 268 268 R 96.4 0.0 4:22.05 stress
182580 upgautam 20 0 3624 268 268 R 70.4 0.0 4:15.51 stress
182571 upgautam 20 0 3624 268 268 R 67.8 0.0 4:29.10 stress
182551 upgautam 20 0 3624 268 268 R 65.1 0.0 4:26.20 stress
182563 upgautam 20 0 3624 268 268 R 65.1 0.0 4:23.85 stress
182545 upgautam 20 0 3624 268 268 R 62.8 0.0 4:27.94 stress
182595 upgautam 20 0 3624 268 268 R 59.9 0.0 4:13.85 stress
182556 upgautam 20 0 3624 268 268 R 57.2 0.0 4:22.13 stress
182544 upgautam 20 0 3624 268 268 R 55.6 0.0 4:19.44 stress
182554 upgautam 20 0 3624 268 268 R 55.3 0.0 4:21.13 stress
182570 upgautam 20 0 3624 268 268 R 55.3 0.0 4:19.09 stress
182552 upgautam 20 0 3624 268 268 R 54.6 0.0 4:33.07 stress
182578 upgautam 20 0 3624 268 268 R 54.3 0.0 4:21.30 stress
182582 upgautam 20 0 3624 268 268 R 53.3 0.0 4:32.94 stress
182575 upgautam 20 0 3624 268 268 R 53.0 0.0 4:25.18 stress
182539 upgautam 20 0 3624 268 268 R 52.3 0.0 4:24.18 stress
182567 upgautam 20 0 3624 268 268 R 52.0 0.0 4:34.91 stress
182577 upgautam 20 0 3624 268 268 R 52.0 0.0 4:18.18 stress
182576 upgautam 20 0 3624 268 268 R 51.6 0.0 4:18.20 stress
182588 upgautam 20 0 3624 268 268 R 51.6 0.0 4:19.34 stress
182553 upgautam 20 0 3624 268 268 R 51.0 0.0 4:25.67 stress
182590 upgautam 20 0 3624 268 268 R 50.7 0.0 4:17.83 stress
182560 upgautam 20 0 3624 268 268 R 50.0 0.0 4:22.09 stress
182599 upgautam 20 0 3624 268 268 R 50.0 0.0 4:28.21 stress
182548 upgautam 20 0 3624 268 268 R 49.3 0.0 4:27.87 stress
182549 upgautam 20 0 3624 268 268 R 49.3 0.0 4:35.70 stress
182579 upgautam 20 0 3624 268 268 R 49.3 0.0 4:21.66 stress
182587 upgautam 20 0 3624 268 268 R 49.0 0.0 4:15.68 stress
182543 upgautam 20 0 3624 268 268 R 48.7 0.0 4:25.76 stress
182598 upgautam 20 0 3624 268 268 R 48.4 0.0 4:23.51 stress
182538 upgautam 20 0 3624 268 268 R 48.0 0.0 4:15.70 stress
182574 upgautam 20 0 3624 268 268 R 48.0 0.0 4:13.55 stress
182547 upgautam 20 0 3624 268 268 R 47.7 0.0 4:27.98 stress
182562 upgautam 20 0 3624 268 268 R 47.4 0.0 4:19.20 stress
182583 upgautam 20 0 3624 268 268 R 47.4 0.0 4:24.88 stress
182555 upgautam 20 0 3624 268 268 R 47.0 0.0 4:29.86 stress
182581 upgautam 20 0 3624 268 268 R 47.0 0.0 4:34.90 stress
182585 upgautam 20 0 3624 268 268 R 47.0 0.0 4:20.67 stress
182589 upgautam 20 0 3624 268 268 R 47.0 0.0 4:24.43 stress
182540 upgautam 20 0 3624 268 268 R 46.7 0.0 4:28.13 stress
182568 upgautam 20 0 3624 268 268 R 46.7 0.0 4:24.50 stress
182572 upgautam 20 0 3624 268 268 R 46.7 0.0 4:23.65 stress
182584 upgautam 20 0 3624 268 268 R 46.7 0.0 4:14.29 stress
182566 upgautam 20 0 3624 268 268 R 46.4 0.0 4:14.20 stress
182591 upgautam 20 0 3624 268 268 R 46.4 0.0 4:19.88 stress
182565 upgautam 20 0 3624 268 268 R 46.1 0.0 4:35.95 stress
182600 upgautam 20 0 3624 268 268 R 46.1 0.0 4:19.81 stress
182601 upgautam 20 0 3624 268 268 R 46.1 0.0 4:35.52 stress
182550 upgautam 20 0 3624 268 268 R 45.7 0.0 4:12.80 stress
182557 upgautam 20 0 3624 268 268 R 45.7 0.0 4:20.87 stress
182564 upgautam 20 0 3624 268 268 R 45.7 0.0 4:17.79 stress
182569 upgautam 20 0 3624 268 268 R 45.7 0.0 4:19.29 stress
182573 upgautam 20 0 3624 268 268 R 45.7 0.0 4:33.64 stress
182593 upgautam 20 0 3624 268 268 R 45.4 0.0 4:21.43 stress
182596 upgautam 20 0 3624 268 268 R 45.1 0.0 4:19.38 stress
182559 upgautam 20 0 3624 268 268 R 44.4 0.0 4:07.59 stress
182594 upgautam 20 0 3624 268 268 R 44.4 0.0 4:24.91 stress
182586 upgautam 20 0 3624 268 268 R 43.4 0.0 4:28.10 stress
182542 upgautam 20 0 3624 268 268 R 35.9 0.0 4:17.32 stress
182541 upgautam 20 0 3624 268 268 R 34.9 0.0 4:21.65 stress
182592 upgautam 20 0 3624 268 268 R 34.9 0.0 4:19.09 stress
182558 upgautam 20 0 3624 268 268 R 34.5 0.0 4:21.57 stress
182546 upgautam 20 0 3624 268 268 R 34.2 0.0 4:15.11 stress
182597 upgautam 20 0 3624 268 268 R 33.9 0.0 4:26.37 stress
4376 upgautam 20 0 4756980 622092 139724 S 6.2 0.5 26:34.20 gnome-shell
157462 upgautam 20 0 1453416 239148 99756 S 4.3 0.2 2:38.21 gnome-system-mo
4109 upgautam 20 0 24.5g 141976 78908 S 3.6 0.1 34:01.36 Xorg
105100 upgautam 20 0 12.4g 1.1g 332440 S 0.7 0.9 35:59.01 firefox
115888 upgautam 20 0 3211704 489856 113588 S 0.7 0.4 5:52.38 Isolated Web Co
147673 upgautam 20 0 818032 85608 50360 S 0.7 0.1 0:05.29 terminator
182625 upgautam 20 0 23348 5972 3668 R 0.7 0.0 0:02.18 top
1434 root 20 0 0 0 0 S 0.3 0.0 6:42.93 nvidia-modeset/kthread_q
1440 root -51 0 0 0 0 S 0.3 0.0 5:13.66 irq/137-nvidia
3989 upgautam 20 0 146888 38268 11288 S 0.3 0.0 3:29.91 pipewire-pulse
123638 upgautam 20 0 2758716 156316 100240 S 0.3 0.1 0:43.87 Isolated Web Co
149019 upgautam 20 0 2951096 500664 118024 S 0.3 0.4 2:11.72 Isolated Web Co
1 root 20 0 25020 15516 9200 S 0.0 0.0 0:07.11 systemd
The flags in the top command represent various statistics that help you understand how processes are using system resources like CPU, memory, and time. Here's a quick summary of the columns:
PID: Process ID
USER: User who owns the process
PR: Priority
NI: Nice value
VIRT: Virtual memory used
RES: Resident memory used (RAM) in MB
SHR: Shared memory used in MB
S: Process status (e.g., sleeping, running)
%CPU: CPU usage percentage
%MEM: Memory usage percentage
TIME+: Total CPU time consumed
COMMAND: Name of the process/command
load average: 64.64, 59.63, 50.94Tasks: 658 total, 65 running, 588 sleeping, 4 stopped, 1 zombie%Cpu(s): 99.5 us, 0.5 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 stMiB Mem : 128541.6 total, 95745.2 free, 25684.1 used, 8468.9 buff/cacheMiB Swap: 94670.0 total, 94670.0 free, 0.0 used. 102857.5 avail Mem182561upgautam200. Nice is similar to chainging process from low to high priority processeses. Setting affinity is choosing CPU core.3624268268R (Running)96.40.04:22.05 (Total accumulated CPU time used by the process)stressUse vmstat x to repeat on every x second
upgautam@amd:~$ vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- -------cpu-------
r b swpd free buff cache si so bi bo in cs us sy id wa st gu
65 0 0 98106304 9432 8689448 0 0 40 200 4789 3 6 0 93 0 0 0
r (running processes): 65
The number of processes that are currently running or ready to run. These processes are waiting for CPU time.
b (blocked processes): 0
The number of processes waiting for I/O resources, such as waiting for data from disk or network.
swpd (swapped memory): 0
No memory is being swapped out to the swap device, which means the system has enough physical memory to handle the processes and is not under memory pressure.
free (free memory): 98106304
The amount of free memory in kilobytes. In this case, there are 98,106,304 KB of free memory, indicating ample available memory for the system.
buff (buffer memory): 9432
The amount of memory used for buffers in kilobytes. Buffers are used to store data that is frequently accessed or written to.
cache (cached memory): 8689448
The amount of memory used for the page cache, which stores data read from disk for faster access.
si (swap in): 0
No data is being moved from swap space to physical memory. The value 0 indicates that the system is not using swap to manage memory.
so (swap out): 0
No data is being moved from physical memory to swap space. This value also indicates the absence of memory pressure.
bi (blocks in): 40
The number of blocks read from the disk per second. In this case, 40 blocks are being read.
bo (blocks out): 200
The number of blocks written to the disk per second. The system is writing at a rate of 200 blocks per second.
in (interrupts): 4789
The number of interrupts per second, including clock interrupts and hardware interrupts. The system is receiving 4789 interrupts per second.
cs (context switches): 3
The number of context switches per second. Context switches happen when the CPU switches between processes. A low value indicates minimal switching, meaning the system is not overloaded.
us (user CPU time): 6
The percentage of CPU time spent on user processes (non-kernel code). In this case, 6% of CPU time is used for user processes.
sy (system CPU time): 0
The percentage of CPU time spent on system processes (kernel code). A value of 0 indicates very little CPU time is spent in kernel mode.
id (idle CPU time): 93
The percentage of CPU time the system is idle, meaning no processes are using the CPU. In this case, the CPU is idle 93% of the time.
wa (waiting for I/O): 0
The percentage of CPU time the system spends waiting for I/O operations to complete. A value of 0 means the CPU is not blocked by I/O.
st (stolen time): 0
The percentage of CPU time "stolen" from the virtual machine by the hypervisor in a virtualized environment. A value of 0 indicates no "stolen" time.
gu (guest CPU time): 0
The amount of CPU time used by virtual machines running on the system. A value of 0 suggests there are no guest virtual machines running.
0, indicating there is no memory pressure.upgautam@amd:~$ iostat
Linux 6.8.0-51-generic (amd) 01/06/2025 _x86_64_ (32 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
7.67 0.00 0.24 0.01 0.00 92.07
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
loop0 0.00 0.01 0.00 0.00 1118 0 0
loop1 0.00 0.00 0.00 0.00 17 0 0
loop10 0.00 0.00 0.00 0.00 13 0 0
loop11 0.00 0.07 0.00 0.00 11585 0 0
loop12 0.00 0.00 0.00 0.00 14 0 0
loop13 0.00 0.00 0.00 0.00 28 0 0
loop14 0.00 0.02 0.00 0.00 2855 0 0
loop15 0.00 0.00 0.00 0.00 13 0 0
loop16 0.00 0.00 0.00 0.00 12 0 0
loop17 0.01 0.52 0.00 0.00 89389 0 0
loop18 0.00 0.00 0.00 0.00 11 0 0
loop19 0.00 0.01 0.00 0.00 1754 0 0
loop2 0.00 0.01 0.00 0.00 1082 0 0
loop20 0.02 0.23 0.00 0.00 40315 0 0
loop21 0.03 0.07 0.00 0.00 11679 0 0
loop22 0.00 0.00 0.00 0.00 44 0 0
loop23 0.00 0.00 0.00 0.00 17 0 0
loop24 0.16 2.44 0.00 0.00 419534 0 0
loop25 0.00 0.00 0.00 0.00 24 0 0
loop26 0.00 0.00 0.00 0.00 11 0 0
loop27 0.00 0.00 0.00 0.00 12 0 0
loop28 0.00 0.00 0.00 0.00 42 0 0
loop29 0.00 0.01 0.00 0.00 1402 0 0
loop3 0.01 0.77 0.00 0.00 133089 0 0
loop30 0.00 0.00 0.00 0.00 11 0 0
loop31 0.00 0.00 0.00 0.00 285 0 0
loop32 0.00 0.00 0.00 0.00 11 0 0
loop33 0.00 0.00 0.00 0.00 13 0 0
loop34 0.00 0.00 0.00 0.00 12 0 0
loop35 0.00 0.00 0.00 0.00 66 0 0
loop36 0.00 0.00 0.00 0.00 10 0 0
loop4 0.00 0.01 0.00 0.00 1075 0 0
loop5 0.00 0.01 0.00 0.00 1115 0 0
loop6 0.00 0.00 0.00 0.00 316 0 0
loop7 0.00 0.00 0.00 0.00 348 0 0
loop8 0.00 0.00 0.00 0.00 29 0 0
loop9 0.00 0.00 0.00 0.00 28 0 0
nvme0n1 4.33 25.90 151.37 5697.50 4461902 26079100 981632712
nvme1n1 0.00 0.02 0.00 0.00 3592 0 0
sda 0.00 0.04 0.00 0.00 7456 0 0
Note: Use modern alternative ss instead of netstat
Below command shows all ESTABLISHED active connections
upgautam@amd:~$ netstat -an | grep ESTABLISHED
tcp 0 0 192.168.0.60:39598 34.107.243.93:443 ESTABLISHED
tcp 0 0 192.168.0.60:56170 192.0.84.247:443 ESTABLISHED
tcp 0 0 192.168.0.62:51492 192.168.0.10:139 ESTABLISHED
tcp 0 0 192.168.0.60:35976 162.159.61.4:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:44208 2606:4700:4400::681:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:33916 2603:1036:303:6::2:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:60294 2600:1f18:24e6:b901:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:44198 2606:4700:4400::681:443 ESTABLISHED
udp 0 0 192.168.0.62:68 192.168.0.1:67 ESTABLISHED
udp 0 0 192.168.0.60:68 192.168.0.1:67 ESTABLISHED
All ESTABLISHED connections on port 443
upgautam@amd:~$ netstat -an | grep ':443' | grep ESTABLISHED
tcp 0 0 192.168.0.60:39598 34.107.243.93:443 ESTABLISHED
tcp 0 0 192.168.0.60:56170 192.0.84.247:443 ESTABLISHED
tcp 0 0 192.168.0.60:35976 162.159.61.4:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:40170 2606:4700:4400::681:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:33916 2603:1036:303:6::2:443 ESTABLISHED
tcp6 0 0 2603:6081:6d01:b7:41184 2606:4700:4400::681:443 ESTABLISHED
grep -c will count the connections. This is like a load to particular server.
upgautam@amd:~$ netstat -an | grep -c ':443'
10
This is similar to iostat or vmstat but it additonally provides hitorical data (i.e., report)
Below command to report on every second for three times.
upgautam@amd:~$ sar -u 1 3
Linux 6.8.0-51-generic (amd) 01/06/2025 _x86_64_ (32 CPU)
10:53:03 AM CPU %user %nice %system %iowait %steal %idle
10:53:04 AM all 0.28 0.00 0.16 0.13 0.00 99.44
10:53:05 AM all 0.16 0.00 0.13 0.00 0.00 99.72
10:53:06 AM all 0.16 0.00 0.16 0.00 0.00 99.69
Average: all 0.20 0.00 0.15 0.04 0.00 99.61
To display from already captured file,
upgautam@amd:~$ sar -u -s 14:00:00 -e 14:30:00 -f /var/log/sysstat/sa03
Linux 6.8.0-51-generic (amd) 01/03/2025 _x86_64_ (32 CPU)
02:00:03 PM CPU %user %nice %system %iowait %steal %idle
02:10:03 PM all 0.00 0.00 0.01 0.00 0.00 99.99
02:20:03 PM all 0.00 0.00 0.01 0.00 0.00 99.99
Average: all 0.00 0.00 0.01 0.00 0.00 99.99
sar: The sar command stands for "System Activity Report" and is used to collect, report, and save system activity information, including CPU usage, memory usage, I/O activity, etc. It provides historical system activity data that can be analyzed later.
-u: This option tells sar to display CPU utilization statistics. Specifically, it shows metrics like CPU usage in terms of user time, system time, idle time, etc.
-s 14:00:00: This specifies the start time for the data you want to display. In this case, it's from 14:00:00 (2:00 PM).
-e 14:30:00: This specifies the end time for the data you want to display. Here, it's set to 14:30:00 (2:30 PM).
-f /var/log/sysstat/sa03: This option tells sar to read the system activity data from a specific file. In this case, the data is read from the file /var/log/sysstat/sa03. These files are created by the sysstat service and store daily system performance data, with sa03 representing the system activity data for the 3rd day of the mqonth.
The sar report can be used to correlate specific events (e.g. check cpu utilization every day in certail time).
General system: Use glances instead of top, htop or atop.
Use mpstat to show real-time just for a session (no reporting, no historical data).
upgautam@amd:~/Desktop$ sudo mpstat -P ALL
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
10:58:28 AM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
10:58:28 AM all 0.56 0.00 0.42 3.03 0.00 0.00 0.00 0.00 0.00 95.99
10:58:28 AM 0 1.70 0.00 1.25 6.51 0.00 0.05 0.00 0.00 0.00 90.48
10:58:28 AM 1 0.23 0.00 0.14 1.73 0.00 0.02 0.00 0.00 0.00 97.87
10:58:28 AM 2 0.30 0.00 0.19 1.29 0.00 0.00 0.00 0.00 0.00 98.22
10:58:28 AM 3 0.10 0.00 0.07 0.31 0.00 0.00 0.00 0.00 0.00 99.52
10:58:28 AM 4 2.04 0.00 1.93 9.88 0.00 0.00 0.00 0.00 0.00 86.14
10:58:28 AM 5 0.28 0.00 0.18 1.07 0.00 0.00 0.00 0.00 0.00 98.47
10:58:28 AM 6 0.27 0.00 0.65 0.79 0.00 0.00 0.00 0.00 0.00 98.29
10:58:28 AM 7 0.42 0.00 0.33 1.39 0.00 0.01 0.00 0.00 0.00 97.85
10:58:28 AM 8 0.33 0.00 0.18 1.82 0.00 0.00 0.00 0.00 0.00 97.67
10:58:28 AM 9 0.17 0.00 0.10 0.56 0.00 0.00 0.00 0.00 0.00 99.17
10:58:28 AM 10 0.53 0.00 0.27 5.44 0.00 0.00 0.00 0.00 0.00 93.75
10:58:28 AM 11 0.14 0.00 0.08 0.43 0.00 0.00 0.00 0.00 0.00 99.35
10:58:28 AM 12 0.09 0.00 0.07 0.27 0.00 0.00 0.00 0.00 0.00 99.57
10:58:28 AM 13 0.67 0.00 0.34 6.88 0.00 0.00 0.00 0.00 0.00 92.11
10:58:28 AM 14 1.18 0.00 0.60 13.18 0.00 0.00 0.00 0.00 0.00 85.04
10:58:28 AM 15 3.49 0.01 2.59 24.33 0.00 0.00 0.00 0.00 0.00 69.58
10:58:28 AM 16 1.21 0.00 1.02 3.63 0.00 0.00 0.00 0.00 0.00 94.14
10:58:28 AM 17 0.18 0.00 0.13 0.24 0.00 0.00 0.00 0.00 0.00 99.45
10:58:28 AM 18 0.14 0.00 0.10 0.13 0.00 0.00 0.00 0.00 0.00 99.64
10:58:28 AM 19 0.07 0.00 0.06 0.03 0.00 0.00 0.00 0.00 0.00 99.84
10:58:28 AM 20 0.92 0.00 0.89 2.59 0.00 0.00 0.00 0.00 0.00 95.60
10:58:28 AM 21 0.10 0.00 0.07 0.22 0.00 0.00 0.00 0.00 0.00 99.61
10:58:28 AM 22 0.10 0.00 0.07 0.15 0.00 0.00 0.00 0.00 0.00 99.67
10:58:28 AM 23 0.14 0.00 0.09 0.22 0.00 0.00 0.00 0.00 0.00 99.55
10:58:28 AM 24 0.56 0.00 0.33 6.70 0.00 0.00 0.00 0.00 0.00 92.42
10:58:28 AM 25 0.23 0.00 0.14 0.84 0.00 0.00 0.00 0.00 0.00 98.78
10:58:28 AM 26 0.21 0.00 0.13 0.60 0.00 0.00 0.00 0.00 0.00 99.06
10:58:28 AM 27 0.10 0.00 0.07 0.11 0.00 0.00 0.00 0.00 0.00 99.72
10:58:28 AM 28 0.07 0.00 0.06 0.14 0.00 0.00 0.00 0.00 0.00 99.73
10:58:28 AM 29 0.14 0.00 0.09 0.45 0.00 0.00 0.00 0.00 0.00 99.32
10:58:28 AM 30 0.26 0.00 0.15 1.43 0.00 0.00 0.00 0.00 0.00 98.16
10:58:28 AM 31 1.42 0.00 1.23 3.66 0.00 0.00 0.00 0.00 0.00 93.68
I can achieve same and more data in different poin of times using sar
upgautam@amd:~/Desktop$ sudo sar -P ALL 1 5
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:01:33 AM CPU %user %nice %system %iowait %steal %idle
11:01:34 AM all 1.86 0.00 1.35 0.25 0.00 96.54
11:01:34 AM 0 2.00 0.00 2.00 0.00 0.00 96.00
11:01:34 AM 1 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 2 0.00 0.00 1.00 0.00 0.00 99.00
11:01:34 AM 3 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 4 10.00 0.00 2.00 0.00 0.00 88.00
11:01:34 AM 5 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 6 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 7 1.01 0.00 0.00 0.00 0.00 98.99
11:01:34 AM 8 2.04 0.00 2.04 0.00 0.00 95.92
11:01:34 AM 9 1.00 0.00 2.00 0.00 0.00 97.00
11:01:34 AM 10 4.12 0.00 3.09 0.00 0.00 92.78
11:01:34 AM 11 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 12 0.00 0.00 1.00 0.00 0.00 99.00
11:01:34 AM 13 3.00 0.00 2.00 0.00 0.00 95.00
11:01:34 AM 14 4.08 0.00 6.12 0.00 0.00 89.80
11:01:34 AM 15 8.16 0.00 8.16 0.00 0.00 83.67
11:01:34 AM 16 1.00 0.00 0.00 0.00 0.00 99.00
11:01:34 AM 17 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 18 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 19 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 20 2.00 0.00 1.00 0.00 0.00 97.00
11:01:34 AM 21 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 22 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 23 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 24 5.05 0.00 1.01 0.00 0.00 93.94
11:01:34 AM 25 1.00 0.00 1.00 0.00 0.00 98.00
11:01:34 AM 26 1.01 0.00 0.00 0.00 0.00 98.99
11:01:34 AM 27 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 28 0.00 0.00 0.00 0.00 0.00 100.00
11:01:34 AM 29 1.02 0.00 2.04 0.00 0.00 96.94
11:01:34 AM 30 7.14 0.00 3.06 8.16 0.00 81.63
11:01:34 AM 31 6.12 0.00 6.12 0.00 0.00 87.76
11:01:34 AM CPU %user %nice %system %iowait %steal %idle
11:01:35 AM all 2.32 0.00 1.35 0.31 0.00 96.02
11:01:35 AM 0 8.25 0.00 1.03 0.00 0.00 90.72
11:01:35 AM 1 2.00 0.00 0.00 0.00 0.00 98.00
11:01:35 AM 2 2.00 0.00 1.00 0.00 0.00 97.00
11:01:35 AM 3 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 4 8.91 0.00 0.99 0.00 0.00 90.10
11:01:35 AM 5 1.00 0.00 0.00 0.00 0.00 99.00
11:01:35 AM 6 1.00 0.00 1.00 0.00 0.00 98.00
11:01:35 AM 7 1.98 0.00 0.99 0.00 0.00 97.03
11:01:35 AM 8 2.97 0.00 1.98 0.00 0.00 95.05
11:01:35 AM 9 1.02 0.00 0.00 0.00 0.00 98.98
11:01:35 AM 10 4.00 0.00 2.00 0.00 0.00 94.00
11:01:35 AM 11 1.01 0.00 0.00 0.00 0.00 98.99
11:01:35 AM 12 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 13 2.02 0.00 1.01 1.01 0.00 95.96
11:01:35 AM 14 5.15 0.00 3.09 0.00 0.00 91.75
11:01:35 AM 15 14.29 0.00 12.24 9.18 0.00 64.29
11:01:35 AM 16 1.00 0.00 0.00 0.00 0.00 99.00
11:01:35 AM 17 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 18 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 19 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 20 0.99 0.00 0.99 0.00 0.00 98.02
11:01:35 AM 21 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 22 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 23 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 24 5.94 0.00 4.95 0.00 0.00 89.11
11:01:35 AM 25 0.00 0.00 0.00 0.00 0.00 100.00
11:01:35 AM 26 2.00 0.00 2.00 0.00 0.00 96.00
11:01:35 AM 27 0.00 0.00 0.99 0.00 0.00 99.01
11:01:35 AM 28 1.00 0.00 0.00 0.00 0.00 99.00
11:01:35 AM 29 1.00 0.00 2.00 0.00 0.00 97.00
11:01:35 AM 30 3.06 0.00 2.04 0.00 0.00 94.90
11:01:35 AM 31 4.08 0.00 5.10 0.00 0.00 90.82
instead of -P ALL use -d for for IO wait and device activity, -r for memory, -n DEV (or -n TCP, UDP) for network, -q for load average, -B for swap memory, and several other. As you can see sar is much more powerful than mpstat.
# network error statistics
upgautam@amd:~/Desktop$ sudo sar -n EDEV 1 1
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:05:51 AM IFACE rxerr/s txerr/s coll/s rxdrop/s txdrop/s txcarr/s rxfram/s rxfifo/s txfifo/s
11:05:52 AM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:05:52 AM enp14s0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:05:52 AM enp15s0f0np0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:05:52 AM enp15s0f1np1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:05:52 AM wlp13s0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:05:52 AM virbr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
upgautam@amd:~/Desktop$ sudo sar -n DEV 1 1
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:24:59 AM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s %ifutil
11:25:00 AM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:25:00 AM enp14s0 1.00 0.00 0.21 0.00 0.00 0.00 0.00 0.00
11:25:00 AM enp15s0f0np0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:25:00 AM enp15s0f1np1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:25:00 AM wlp13s0 1.00 0.00 0.21 0.00 0.00 0.00 0.00 0.00
11:25:00 AM virbr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
11:25:00 AM cvd-ebr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Swap memroy,
# swap memory
upgautam@amd:~/Desktop$ sudo sar -B 1 1
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:21:59 AM pgpgin/s pgpgout/s fault/s majflt/s pgfree/s pgscank/s pgscand/s pgsteal/s %vmeff
11:22:00 AM 0.00 80.00 6772.00 0.00 4836.00 0.00 0.00 0.00 0.00
Average: 0.00 80.00 6772.00 0.00 4836.00 0.00 0.00 0.00 0.00
Load average,
# load average
upgautam@amd:~/Desktop$ sudo sar -q 1 1
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:23:52 AM runq-sz plist-sz ldavg-1 ldavg-5 ldavg-15 blocked
11:23:53 AM 0 1748 0.21 0.23 0.71 0
Average: 0 1748 0.21 0.23 0.71 0
TCP, UPD statistics,
# tcp,udp
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:24:31 AM active/s passive/s iseg/s oseg/s
11:24:32 AM 0.00 0.00 0.00 0.00
11:24:31 AM idgm/s odgm/s noport/s idgmerr/s
11:24:32 AM 0.00 0.00 0.00 0.00
Average: active/s passive/s iseg/s oseg/s
Average: 0.00 0.00 0.00 0.00
Average: idgm/s odgm/s noport/s idgmerr/s
Average: 0.00 0.00 0.00 0.00
Memory related,
upgautam@amd:~/Desktop$ sudo sar -r 1 2
Linux 6.8.0-51-generic (amd) 01/08/2025 _x86_64_ (32 CPU)
11:25:54 AM kbmemfree kbavail kbmemused %memused kbbuffers kbcached kbcommit %commit kbactive kbinact kbdirty
11:25:55 AM 12096124 120977676 8043672 6.11 2729192 99150312 16762700 7.33 10142156 98143196 1504
11:25:56 AM 12098148 120979700 8041648 6.11 2729192 99150312 16762704 7.33 10142256 98143196 1504
Average: 12097136 120978688 8042660 6.11 2729192 99150312 16762702 7.33 10142206 98143196 1504
or use free for simple output
About 12 GB free, 120 GB available, and 8 GB used. Available = free + reclaimable cache/buffer + some other tracked by system Free = completely unused RAM
** Note**: Use lscpu to get detailed CPU information.
upgautam@amd:~/Desktop$ sudo turbostat
turbostat version 2023.11.07 - Len Brown <lenb@kernel.org>
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.8.0-51-generic root=UUID=b16a83dc-3b3d-4d1a-8bb3-7b1facd0d8fe ro quiet splash amd_iommu=on iommu=pt vt.handoff=7
CPUID(0): AuthenticAMD 0x10 CPUID levels
CPUID(1): family:model:stepping 0x19:61:2 (25:97:2) microcode 0x0
CPUID(0x80000000): max_extended_levels: 0x80000028
CPUID(1): SSE3 MONITOR - - - TSC MSR - HT -
CPUID(6): APERF, No-TURBO, No-DTS, No-PTM, No-HWP, No-HWPnotify, No-HWPwindow, No-HWPepp, No-HWPpkg, No-EPB
CPUID(7): No-SGX No-Hybrid
cpu0: cpufreq driver: amd-pstate-epp
cpu0: cpufreq governor: performance
/dev/cpu_dma_latency: 2000000000 usec (default)
current_driver: acpi_idle
current_governor: menu
current_governor_ro: menu
cpu0: POLL: CPUIDLE CORE POLL IDLE
cpu0: C1: ACPI FFH MWAIT 0x0
cpu0: C2: ACPI IOPORT 0x414
cpu0: C3: ACPI IOPORT 0x415
RAPL: 234 sec. Joule Counter Range, at 280 Watts
cpu0: MSR_RAPL_PWR_UNIT: 0x000a1000 (1.000000 Watts, 0.000015 Joules, 0.000977 sec.)
Core CPU Avg_MHz Busy% Bzy_MHz TSC_MHz IPC IRQ POLL C1 C2 C3 POLL% C1% C2% C3% CorWatt PkgWatt
- - 62 1.12 5475 4489 1.02 28309 116 1755 3643 18456 0.00 0.33 0.64 97.90 5.3053.92
0 0 275 4.97 5527 4491 0.86 4695 11 29 140 1719 0.01 0.05 1.21 93.95 0.6853.95
0 16 6 0.11 5468 4491 0.17 250 41 10 24 162 0.01 0.00 0.07 99.69
1 1 28 0.50 5544 4491 0.97 282 0 1 9 234 0.00 0.00 0.12 99.41 0.09
1 17 2 0.03 5495 4491 0.27 56 0 2 19 33 0.00 0.00 0.25 99.73
2 2 67 1.21 5575 4491 1.14 220 0 0 10 127 0.00 0.00 0.08 98.72 0.15
2 18 1 0.02 5455 4491 0.29 30 0 0 2 26 0.00 0.00 0.00 99.97
3 3 4 0.08 5468 4491 0.23 206 8 75 0 117 0.00 0.15 0.00 99.79 0.05
3 19 1 0.01 5485 4491 0.24 17 0 0 4 11 0.00 0.00 0.02 99.97
4 4 179 3.21 5571 4491 1.17 1011 9 30 82 666 0.01 0.10 0.51 96.23 0.78
4 20 66 1.21 5489 4491 0.33 2444 9 24 913 1448 0.01 0.14 5.59 93.20
5 5 5 0.09 5491 4491 0.51 65 0 1 12 47 0.00 0.00 0.04 99.88 0.06
5 21 13 0.23 5415 4491 0.52 268 0 2 37 184 0.00 0.00 0.21 99.58
6 6 6 0.11 5478 4491 0.47 109 0 3 27 64 0.00 0.01 0.15 99.74 0.06
6 22 12 0.22 5500 4491 0.42 169 0 1 7 153 0.00 0.00 0.10 99.69
7 7 40 0.74 5480 4491 1.65 384 1 28 18 260 0.00 0.01 0.15 99.13 0.12
7 23 0 0.01 5442 4491 0.24 19 0 1 2 14 0.00 0.00 0.01 99.98
8 8 45 0.83 5463 4491 0.71 730 0 3 63 604 0.00 0.00 0.76 98.47 0.23
8 24 59 1.08 5478 4491 0.93 933 3 133 70 698 0.00 0.83 0.70 97.44
9 9 4 0.07 5449 4491 0.75 40 0 0 2 30 0.00 0.00 0.02 99.91 0.18
9 25 57 1.03 5472 4491 0.53 1815 3 119 519 1162 0.00 0.59 2.20 96.29
10 10 80 1.47 5466 4491 0.95 895 1 96 54 678 0.00 0.47 0.64 97.47 0.43
10 26 67 1.23 5478 4491 0.42 2319 4 199 646 1453 0.00 1.87 1.30 95.76
11 11 15 0.28 5478 4491 0.40 437 0 0 17 401 0.00 0.00 0.13 99.63 0.09
11 27 37 0.68 5481 4491 0.47 1055 0 54 167 813 0.00 0.30 0.69 98.41
12 12 0 0.01 5453 4491 0.33 14 0 0 3 9 0.00 0.00 0.02 99.98 0.13
12 28 23 0.42 5479 4491 0.49 737 0 43 27 648 0.00 0.25 0.15 99.22
13 13 96 1.75 5471 4491 0.87 1809 4 248 113 1436 0.00 1.42 0.87 96.06 0.55
13 29 31 0.57 5465 4491 0.59 1148 2 19 139 971 0.00 0.06 0.86 98.57
14 14 120 2.20 5447 4491 1.05 1239 2 216 83 897 0.00 1.74 0.90 95.23 0.41
14 30 38 0.69 5466 4491 0.81 921 5 17 46 790 0.00 0.15 0.47 98.73
15 15 555 10.24 5424 4491 1.47 2454 8 69 274 1379 0.00 0.44 1.83 87.60 1.30
15 31 37 0.68 5458 4491 0.61 1538 5 332 114 1222 0.00 1.90 0.50 97.00
I wrote separate post for perf already in my website.
upgautam@amd:~/Desktop$ sudo smem
PID User Command Swap USS PSS RSS
1680 root /usr/sbin/atopacctd 0 136 144 1484
2640 root /bin/sh /snap/cups/1067/scr 0 60 155 1044
3891 root fusermount3 -o rw,nosuid,no 0 152 166 2164
2260 root /bin/sh /snap/cups/1067/scr 0 64 193 1756
88893 root sleep 3600 0 140 218 1924
2261 root /bin/sh /snap/cups/1067/scr 0 128 223 1744
49523 upgautam sh -c /usr/bin/pager 0 232 241 1924
59215 upgautam /usr/lib/speech-dispatcher- 0 220 243 2800
3121 root /usr/bin/netserver 0 272 277 1168
1634 root /usr/sbin/cron -f -P 0 300 319 3064
2462 root /usr/sbin/dnsmasq --conf-fi 0 88 360 1296
1669 avahi avahi-daemon: chroot helper 0 140 380 1596
89204 root /usr/lib/linux-tools/6.8.0- 0 372 384 2364
2577 rtkit /usr/libexec/rtkit-daemon 0 356 388 3684
2461 libvirt-dnsmasq /usr/sbin/dnsmasq --conf-fi 0 132 477 2340
47050 root dbus-launch --autolaunch 8f 0 456 487 2596
4158 upgautam /usr/libexec/gnome-session- 0 476 519 5924
47051 root /usr/bin/dbus-daemon --sysl 0 464 536 2752
3115 kernoops /usr/sbin/kerneloops 0 484 550 2412
3097 kernoops /usr/sbin/kerneloops --test 0 492 558 2496
2209 nvidia-persistenced /usr/bin/nvidia-persistence 0 580 590 2248
49524 upgautam /usr/bin/pager 0 548 603 2860
3949 upgautam /usr/libexec/gdm-x-session 0 576 627 6608
3418 nobody dnsmasq --port=0 --strict-o 0 532 649 2284
3881 upgautam /usr/libexec/xdg-permission 0 608 651 6436
3217 nobody dnsmasq --port=0 --strict-o 0 536 655 2292
1586 _rpc /sbin/rpcbind -f -w 0 584 656 4212
4340 upgautam /usr/libexec/gsd-screensave 0 624 674 6648
4317 upgautam /usr/libexec/gsd-a11y-setti 0 648 706 7012
90180 root sudo smem 0 108 749 2744
46915 root sudo perf report 0 112 751 2844
54374 root sudo perf top -e cycles:P 0 112 751 2840
89203 root sudo turbostat 0 120 754 2828
77498 upgautam /usr/bin/gpg-agent --superv 0 688 773 3644
1635 root /usr/libexec/switcheroo-con 0 752 827 7196
4573 upgautam /usr/libexec/gvfs-goa-volum 0 740 842 6828
4157 upgautam /usr/libexec/gcr-ssh-agent 0 756 845 7268
gprof is a type of application and code profiling tool. Other tools include strace, ltrace, valgrind, oprofile, systemtap, eBPF tools, perf record, time etc.
If you want to profile your own source code and want to know what functions takes more time, and where is the improvement places to fix etc.
// advanced_gprof_example.c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 1000 // Size of array/matrix
// Function to calculate sum of an array
void calculate_sum(int *arr, int size) {
long long sum = 0;
for (int i = 0; i < size; i++) {
sum += arr[i];
}
}
// Function to perform matrix multiplication
void matrix_multiply(int **A, int **B, int **C, int n) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
C[i][j] = 0;
for (int k = 0; k < n; k++) {
C[i][j] += A[i][k] * B[k][j];
}
}
}
}
int main() {
// Dynamically allocate memory for array and matrices
int *arr = (int *)malloc(N * sizeof(int));
int **A = (int **)malloc(N * sizeof(int *));
int **B = (int **)malloc(N * sizeof(int *));
int **C = (int **)malloc(N * sizeof(int *));
for (int i = 0; i < N; i++) {
A[i] = (int *)malloc(N * sizeof(int));
B[i] = (int *)malloc(N * sizeof(int));
C[i] = (int *)malloc(N * sizeof(int));
}
// Initialize the array and matrices with random values
srand(time(NULL));
for (int i = 0; i < N; i++) {
arr[i] = rand() % 100;
for (int j = 0; j < N; j++) {
A[i][j] = rand() % 100;
B[i][j] = rand() % 100;
}
}
// Start profiling for the functions
calculate_sum(arr, N); // Sum calculation
matrix_multiply(A, B, C, N); // Matrix multiplication
// Free dynamically allocated memory
free(arr);
for (int i = 0; i < N; i++) {
free(A[i]);
free(B[i]);
free(C[i]);
}
free(A);
free(B);
free(C);
return 0;
}
Compile and run
upgautam@amd:~/Desktop/perf$ gcc -pg -o advanced_gprof_example advanced_gprof_example.c
upgautam@amd:~/Desktop/perf$ ls
advanced_gprof_example allevents.txt perf.data perf_script_output.txt
advanced_gprof_example.c FlameGraph perf.data.old perf.svg
upgautam@amd:~/Desktop/perf$ ./advanced_gprof_example
upgautam@amd:~/Desktop/perf$ gprof advanced_gprof_example gmon.out > profile_report.txt
upgautam@amd:~/Desktop/perf$ ls
advanced_gprof_example allevents.txt gmon.out perf.data.old perf.svg
advanced_gprof_example.c FlameGraph perf.data perf_script_output.txt profile_report.txt
upgautam@amd:~/Desktop/perf$ cat profile_report.txt
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls s/call s/call name
99.57 2.33 2.33 1 2.33 2.33 matrix_multiply
0.43 2.34 0.01 _init
0.00 2.34 0.00 1 0.00 0.00 calculate_sum
% the percentage of the total running time of the
time program used by this function.
cumulative a running sum of the number of seconds accounted
seconds for by this function and those listed above it.
self the number of seconds accounted for by this
seconds function alone. This is the major sort for this
listing.
calls the number of times this function was invoked, if
this function is profiled, else blank.
self the average number of milliseconds spent in this
ms/call function per call, if this function is profiled,
else blank.
total the average number of milliseconds spent in this
ms/call function and its descendents per call, if this
function is profiled, else blank.
name the name of the function. This is the minor sort
for this listing. The index shows the location of
the function in the gprof listing. If the index is
in parenthesis it shows where it would appear in
the gprof listing if it were to be printed.
Copyright (C) 2012-2024 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
Call graph (explanation follows)
granularity: each sample hit covers 4 byte(s) for 0.43% of 2.34 seconds
index % time self children called name
2.33 0.00 1/1 main [2]
[1] 99.6 2.33 0.00 1 matrix_multiply [1]
-----------------------------------------------
<spontaneous>
[2] 99.6 0.00 2.33 main [2]
2.33 0.00 1/1 matrix_multiply [1]
0.00 0.00 1/1 calculate_sum [4]
-----------------------------------------------
<spontaneous>
[3] 0.4 0.01 0.00 _init [3]
-----------------------------------------------
0.00 0.00 1/1 main [2]
[4] 0.0 0.00 0.00 1 calculate_sum [4]
-----------------------------------------------
This table describes the call tree of the program, and was sorted by
the total amount of time spent in each function and its children.
Each entry in this table consists of several lines. The line with the
index number at the left hand margin lists the current function.
The lines above it list the functions that called this function,
and the lines below it list the functions this one called.
This line lists:
index A unique number given to each element of the table.
Index numbers are sorted numerically.
The index number is printed next to every function name so
it is easier to look up where the function is in the table.
% time This is the percentage of the `total' time that was spent
in this function and its children. Note that due to
different viewpoints, functions excluded by options, etc,
these numbers will NOT add up to 100%.
self This is the total amount of time spent in this function.
children This is the total amount of time propagated into this
function by its children.
called This is the number of times the function was called.
If the function called itself recursively, the number
only includes non-recursive calls, and is followed by
a `+' and the number of recursive calls.
name The name of the current function. The index number is
printed after it. If the function is a member of a
cycle, the cycle number is printed between the
function's name and the index number.
For the function's parents, the fields have the following meanings:
self This is the amount of time that was propagated directly
from the function into this parent.
children This is the amount of time that was propagated from
the function's children into this parent.
called This is the number of times this parent called the
function `/' the total number of times the function
was called. Recursive calls to the function are not
included in the number after the `/'.
name This is the name of the parent. The parent's index
number is printed after it. If the parent is a
member of a cycle, the cycle number is printed between
the name and the index number.
If the parents of the function cannot be determined, the word
`<spontaneous>' is printed in the `name' field, and all the other
fields are blank.
For the function's children, the fields have the following meanings:
self This is the amount of time that was propagated directly
from the child into the function.
children This is the amount of time that was propagated from the
child's children to the function.
called This is the number of times the function called
this child `/' the total number of times the child
was called. Recursive calls by the child are not
listed in the number after the `/'.
name This is the name of the child. The child's index
number is printed after it. If the child is a
member of a cycle, the cycle number is printed
between the name and the index number.
If there are any cycles (circles) in the call graph, there is an
entry for the cycle-as-a-whole. This entry shows who called the
cycle (as parents) and the members of the cycle (as children.)
The `+' recursive calls entry shows the number of function calls that
were internal to the cycle, and the calls entry for each member shows,
for that member, how many times it was called from other members of
the cycle.
Copyright (C) 2012-2024 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
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Index by function name
[3] _init [4] calculate_sum [1] matrix_multiply