1. Article purpose
This article provides the basic information needed to start using the Linux® tool: top[1].
2. Introduction
The following table provides a brief description of the tool, as well as its availability depending on the software packages:
: this tool is either present (ready to use or to be activated), or can be integrated and activated on the software package.
: this tool is not present and cannot be integrated, or it is present but cannot be activated on the software package.
| Tool | STM32MPU Embedded Software distribution | STM32MPU Embedded Software distribution for Android™ | ||||||
|---|---|---|---|---|---|---|---|---|
| Name | Category | Purpose | Starter Package | Developer Package | Distribution Package | Starter Package | Developer Package | Distribution Package |
| top | Monitoring tools | The top[1] program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of tasks currently being managed by the Linux kernel. The types of system summary information shown and the types, order and size of information displayed for tasks are all user configurable and that configuration can be made persistent across restarts. (Extracted from man page[1]) | |
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3. Installing the trace and debug tool on your target board
3.1. Using the STM32MPU Embedded Software Distribution
top is installed by default and is ready to be used with all STM32MPU Embedded Software Packages.
which top /usr/bin/top
It is integrated into the Weston image distribution by using the following meta-st package recipe to enable the procps module: layers/meta-st/meta-st-openstlinux/recipes-st/packagegroups/packagegroup-framework-tools.bb.
RDEPENDS_packagegroup-framework-tools-core = "\
grep \
util-linux \
util-linux-lscpu \
procps \
kbd \
...
3.2. Using the STM32MPU Embedded Software distribution for Android™
top is installed by default and ready to be used with all STM32MPU Embedded Software Packages for Android™.
It comes with the toybox:
which top | xargs ls -la /system/bin/top -> toybox
4. Getting started
- Displaying individual threads: without this command-line option a summation of all threads in each process is shown
top -H
top - 16:50:23 up 4:31, 1 user, load average: 0.38, 0.38, 0.37
Threads: 130 total, 1 running, 129 sleeping, 0 stopped, 0 zombie
%Cpu(s): 4.3 us, 10.9 sy, 0.0 ni, 84.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 871.9 total, 673.1 free, 107.7 used, 91.2 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 736.6 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
895 root 20 0 2652 1608 1220 R 25.0 0.2 0:00.08 top
1 root 20 0 24164 4808 3104 S 0.0 0.5 0:17.88 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.03 kthreadd
3 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_gp
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rcu_par_gp
6 root 0 -20 0 0 0 I 0.0 0.0 0:00.01 kworker/0:0H-kblockd
7 root 20 0 0 0 0 I 0.0 0.0 0:00.04 kworker/u4:0-events_unbound
8 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 mm_percpu_wq
9 root 20 0 0 0 0 S 0.0 0.0 0:01.42 ksoftirqd/0
10 root 20 0 0 0 0 I 0.0 0.0 0:03.19 rcu_preempt
11 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_sched
12 root 20 0 0 0 0 I 0.0 0.0 0:00.00 rcu_bh
13 root rt 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/0
15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 cpuhp/1
16 root rt 0 0 0 0 S 0.0 0.0 0:00.00 migration/1
17 root 20 0 0 0 0 S 0.0 0.0 0:01.64 ksoftirqd/1
19 root 0 -20 0 0 0 I 0.0 0.0 0:00.07 kworker/1:0H-kblockd
20 root 20 0 0 0 0 S 0.0 0.0 0:00.04 kdevtmpfs
21 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 netns
22 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_tasks_kthre
24 root 20 0 0 0 0 S 0.0 0.0 0:00.00 oom_reaper
25 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 writeback
26 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kcompactd0
27 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 crypto
28 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kblockd
29 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 ata_sff
30 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 edac-poller
31 root rt 0 0 0 0 S 0.0 0.0 0:00.00 watchdogd
32 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 rpciod
33 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/u5:0
34 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 xprtiod
35 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kswapd0
36 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 nfsiod
- Displaying only given PID:
top -p<PID>
Note that several PIDs can be given by using the following syntax:
top -p<PID1>,<PID2>,<PID3>...
<PID> can be a given known PID value. pidof macro may be useful in this case to refer to the name of process rather than the integer value. Use -S',' option to join PID values with ',' instead of whitespace.
top -p`pidof -S',' netdata` top - 16:59:39 up 4:40, 1 user, load average: 0.46, 0.46, 0.41 Tasks: 1 total, 0 running, 1 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.0 us, 2.9 sy, 0.0 ni, 97.1 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st MiB Mem : 871.9 total, 673.2 free, 107.6 used, 91.2 buff/cache MiB Swap: 0.0 total, 0.0 free, 0.0 used. 736.6 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 389 root 20 0 131340 15528 2036 S 0.0 1.7 2:39.63 netdata
and by adding -H option:
top -p`pidof -S',' netdata` -H top - 16:58:15 up 4:39, 1 user, load average: 0.62, 0.48, 0.41 Threads: 12 total, 0 running, 12 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.3 us, 0.5 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st MiB Mem : 871.9 total, 673.1 free, 107.6 used, 91.2 buff/cache MiB Swap: 0.0 total, 0.0 free, 0.0 used. 736.6 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 407 root 20 0 131340 15528 2036 S 0.3 1.7 1:06.85 netdata 409 root 20 0 131340 15528 2036 S 0.3 1.7 0:46.08 netdata 389 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.23 netdata 406 root 20 0 131340 15528 2036 S 0.0 1.7 0:13.30 netdata 408 root 20 0 131340 15528 2036 S 0.0 1.7 0:05.31 netdata 411 root 20 0 131340 15528 2036 S 0.0 1.7 0:03.51 netdata 412 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.09 netdata 413 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.08 netdata 414 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.92 netdata 418 root 20 0 131340 15528 2036 S 0.0 1.7 0:01.24 netdata 419 root 20 0 131340 15528 2036 S 0.0 1.7 0:21.12 netdata 425 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.00 netdata
- Sorting informations
When the top command result is displayed, type "F", then select a filter: please see highlighted part below:
Fields Management for window 1:Def, whose current sort field is %CPU Navigate with Up/Dn, Right selects for move then <Enter> or Left commits, 'd' or <Space> toggles display, 's' sets sort. Use 'q' or <Esc> to end! * PID = Process Id SUPGRPS = Supp Groups Names * USER = Effective User Name TGID = Thread Group Id * PR = Priority OOMa = OOMEM Adjustment * NI = Nice Value OOMs = OOMEM Score current * VIRT = Virtual Image (KiB) ENVIRON = Environment vars * RES = Resident Size (KiB) vMj = Major Faults delta * SHR = Shared Memory (KiB) vMn = Minor Faults delta * S = Process Status USED = Res+Swap Size (KiB) * %CPU = CPU Usage nsIPC = IPC namespace Inode * %MEM = Memory Usage (RES) nsMNT = MNT namespace Inode * TIME+ = CPU Time, hundredths nsNET = NET namespace Inode * COMMAND = Command Name/Line nsPID = PID namespace Inode PPID = Parent Process pid nsUSER = USER namespace Inode UID = Effective User Id nsUTS = UTS namespace Inode RUID = Real User Id LXC = LXC container name RUSER = Real User Name RSan = RES Anonymous (KiB) SUID = Saved User Id RSfd = RES File-based (KiB) SUSER = Saved User Name RSlk = RES Locked (KiB) GID = Group Id RSsh = RES Shared (KiB) GROUP = Group Name CGNAME = Control Group name PGRP = Process Group Id NU = Last Used NUMA node TTY = Controlling Tty TPGID = Tty Process Grp Id SID = Session Id nTH = Number of Threads P = Last Used Cpu (SMP) TIME = CPU Time SWAP = Swapped Size (KiB) CODE = Code Size (KiB) DATA = Data+Stack (KiB) nMaj = Major Page Faults nMin = Minor Page Faults nDRT = Dirty Pages Count WCHAN = Sleeping in Function Flags = Task Flags <sched.h> CGROUPS = Control Groups SUPGIDS = Supp Groups IDs
- Displaying where threads are sleeping
When the top command result is displayed, type "F", then go to the WCHAN parameter. Finally type "d" or <space> to toggle the display of this field and "q" or <esc> to get back to top table display.
Fields Management for window 1:Def, whose current sort field is %CPU Navigate with Up/Dn, Right selects for move then <Enter> or Left commits, 'd' or <Space> toggles display, 's' sets sort. Use 'q' or <Esc> to end! * PID = Process Id SUPGRPS = Supp Groups Names * USER = Effective User Name TGID = Thread Group Id * PR = Priority OOMa = OOMEM Adjustment * NI = Nice Value OOMs = OOMEM Score current * VIRT = Virtual Image (KiB) ENVIRON = Environment vars * RES = Resident Size (KiB) vMj = Major Faults delta * SHR = Shared Memory (KiB) vMn = Minor Faults delta * S = Process Status USED = Res+Swap Size (KiB) * %CPU = CPU Usage nsIPC = IPC namespace Inode * %MEM = Memory Usage (RES) nsMNT = MNT namespace Inode * TIME+ = CPU Time, hundredths nsNET = NET namespace Inode * COMMAND = Command Name/Line nsPID = PID namespace Inode PPID = Parent Process pid nsUSER = USER namespace Inode UID = Effective User Id nsUTS = UTS namespace Inode RUID = Real User Id LXC = LXC container name RUSER = Real User Name RSan = RES Anonymous (KiB) SUID = Saved User Id RSfd = RES File-based (KiB) SUSER = Saved User Name RSlk = RES Locked (KiB) GID = Group Id RSsh = RES Shared (KiB) GROUP = Group Name CGNAME = Control Group name PGRP = Process Group Id NU = Last Used NUMA node TTY = Controlling Tty TPGID = Tty Process Grp Id SID = Session Id nTH = Number of Threads P = Last Used Cpu (SMP) TIME = CPU Time SWAP = Swapped Size (KiB) CODE = Code Size (KiB) DATA = Data+Stack (KiB) nMaj = Major Page Faults nMin = Minor Page Faults nDRT = Dirty Pages Count * WCHAN = Sleeping in Function Flags = Task Flags <sched.h> CGROUPS = Control Groups SUPGIDS = Supp Groups IDs
This option enables the display of wchan.
top -p `pidof -S',' netdata`,`pidof -S',' python3` top - 17:19:15 up 5:00, 1 user, load average: 0.47, 0.45, 0.45 Tasks: 2 total, 0 running, 2 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.3 us, 1.0 sy, 0.0 ni, 98.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st MiB Mem : 871.9 total, 672.9 free, 107.8 used, 91.2 buff/cache MiB Swap: 0.0 total, 0.0 free, 0.0 used. 736.4 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND WCHAN 389 root 20 0 131340 15528 2036 S 0.7 1.7 2:50.72 netdata sys_pause 424 root 20 0 43496 14860 5680 S 0.0 1.7 0:33.02 python3 poll_sche+
- Showing only one iteration of top and putting it in batch mode (useful for putting in a file)
top -p`pidof -S',' netdata` -H -b -n1
top - 17:26:53 up 5:07, 1 user, load average: 0.46, 0.47, 0.45
Threads: 12 total, 0 running, 12 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 2.9 sy, 0.0 ni, 97.1 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 871.9 total, 672.9 free, 107.8 used, 91.2 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 736.5 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
389 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.23 netdata
406 root 20 0 131340 15528 2036 S 0.0 1.7 0:14.67 netdata
407 root 20 0 131340 15528 2036 S 0.0 1.7 1:13.64 netdata
408 root 20 0 131340 15528 2036 S 0.0 1.7 0:05.83 netdata
409 root 20 0 131340 15528 2036 S 0.0 1.7 0:50.85 netdata
411 root 20 0 131340 15528 2036 S 0.0 1.7 0:03.92 netdata
412 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.10 netdata
413 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.09 netdata
414 root 20 0 131340 15528 2036 S 0.0 1.7 0:01.00 netdata
418 root 20 0 131340 15528 2036 S 0.0 1.7 0:01.38 netdata
419 root 20 0 131340 15528 2036 S 0.0 1.7 0:23.24 netdata
425 root 20 0 131340 15528 2036 S 0.0 1.7 0:00.00 netdata
5. References