A command-line system monitor tool that produces a frequently-updated list of processes.

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127
votes
7answers
149k views

How to display `top` results sorted by memory usage in real time?

How can I display the top results in my terminal in real time so that the list is sorted by memory usage?
103
votes
1answer
125k views

In Linux “top” command what are us, sy, ni, id, wa, hi, si and st (for CPU usage)?

When I issue $ top in linux, I get a result similar to this (see here). One of the lines has CPU usage information represented like this: Cpu(s): 87.3%us, 1.2%sy, 0.0%ni, 27.6%id, 0.0%wa, ...
61
votes
6answers
60k views

How to display meminfo in megabytes in top?

Sometimes it is not comfortable to see meminfo in kilobytes while you have several gigs of RAM. In Linux it looks like that: And here is how it looks in Mac OS X: Is there a way to display ...
59
votes
2answers
20k views

Why does `htop` show more process than `ps`

In ps xf 26395 pts/78 Ss 0:00 \_ bash 27016 pts/78 Sl+ 0:04 | \_ unicorn_rails master -c config/unicorn.rb 27042 pts/78 Sl+ 0:00 | ...
58
votes
6answers
93k views

How to monitor CPU/memory usage of a single process?

I would like to monitor one process's memory / cpu usage in real time. Similar to top but targeted at only one process, preferably with a history graph of some sort.
46
votes
6answers
125k views

How to find which processes are taking all the memory?

I'm looking for somthing like top is to CPU usage. Is there a command line argument for top that does this? Currently, my memory is so full that even 'man top' fails with out of memory :)
28
votes
1answer
17k views

Human readable memory sizes in top? [duplicate]

Is there an option in top to show memory sizes in human readable format? Example: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3960 phil ...
26
votes
2answers
37k views

What units of time does “top” use?

If I issue the "top" command and receive results such as: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 00001 bob 25 0 77380 1212 1200 R 95.8 0.0 89122:13 fee ...
25
votes
2answers
32k views

Top and ps not showing the same cpu result

This is linked to this question. When I run top I get the following result: pid 3038 is using 18% cpu, however when running the result is 5.5%. And this number does not appear to be changing ...
25
votes
1answer
5k views

Meaning of colours in htop

Given the option: [ ] Detailed CPU time (System/IO-Wait/Hard-IRQ/Soft-IRQ/Steal/Guest) In htop (Version 1.0.1) what are the meanings of the colours? In the following image, I'm seeing rather a lot ...
15
votes
6answers
13k views

How to make a process invisible to other users?

How could you launch a process and make it invisible to the top command? The process is started by a normal user (not root), and should not be visible to other normal users.
14
votes
2answers
12k views

How to know reason of a process going to sleep state and wake it up?

When I do 'top' , I see my perl script process in 'S' state. Is there a way to know, what is making this perl process go in sleep state and ways to wake it up? Any way to debug to give more insights ...
11
votes
5answers
31k views

Change top's sorting back to CPU

A former coworker did something to top that whenever it runs as root the data is sorted by MEM usage instead of the default CPU usage. According to multiple searches, the man page and even the options ...
11
votes
4answers
6k views

How can I receive top-like CPU statistics from the shell?

I'm trying to get an accurate read of my used CPU (in percent) from top. This is the command I'm running for testing: top -n1 | awk '/Cpu\(s\):/ {print $2}' This returns: 10.7%us, Which is the ...
11
votes
2answers
2k views

Tools for Monitoring Steal Time (st)

We're running on a virtual "dedicated" server, which should, in theory, mean that we're the only guys on the server. In practice.... I'm thinking we might not be. Notice that although it looks ...
10
votes
1answer
35k views

top command on multi core processor

I am using freescale IMX6 quad processor. I want to know if the top command lists the CPU usage of all 4 cores or of a single core. I am seeing an application's CPU usage being the same with 4 cores ...
10
votes
1answer
2k views

How to stream top snapshot into file?

Is there any way to persist the snapshot of top at that given moment into a file? I tried top > top.out but the contents were nothing like top in STDOUT: ^[[H^[[2J^[(B^[[mtop - 16:09:49 up 18 ...
9
votes
2answers
4k views

Why does top report the incorrect CPU usage?

I have a machine with Intel(R) Xeon(R) CPU E5520 visible as 16 logical cores (8 with HT). If I run something to eat CPU time (single threaded) top correctly reports 100% CPU usage for the process but ...
9
votes
3answers
2k views

why does htop meter show >90% while table is 0.0%?

Why do the progress meters across the top of the screen in htop show CPU usage consistently above >90% while the numbers in the table below show a nearly idle system with CPU usage and load average at ...
9
votes
1answer
8k views

Why the value of VSIZE in top is different from the value of VSZ (Virtual set size) in ps?

I know VSZ in ps is for the total address space allocated for the app and is sometimes aliased as vsize (mentioned in man page of ps on linux), but what's the definition of VSIZE in top? This top ...
8
votes
3answers
13k views

How to select specific processes with 'top'?

In case of one program having multiple instances, running pidof program gives: `1 2 3` top -p accepts comma-delimited arguments: 1, 2, 3. This means that top -p `pidof program` won't work: ...
8
votes
2answers
45k views

Understanding %CPU while running top command [duplicate]

I am trying to understand what does %CPU means when I run top. I am seeing %CPU for my application as 400 or 500 most of the times. Does anyone knows what does this mean? What number is a high ...
8
votes
4answers
3k views

Alert when running process finishes

There are a few questions and answers on here with regard to being alerted when a process completes/exits(1, 2) – but these all assume that the user has issued said process themselves, and thus can ...
8
votes
4answers
10k views

How do I get “top” command to wrap its output?

The "command" column gets truncated by the width of the screen and I am unable to see the last part of it. I have tried to reduce the font size so I can see a longer part of the command line but it ...
8
votes
5answers
4k views

Understanding top and load average

I'm observing a high load average on a certain machine (about 9) in all three load fields. I understand load as the number of processes in state "run" / currently desiring CPU time. Am I correct at ...
8
votes
2answers
1k views

How to find out how much memory a program taking

I use htop to watch my processes, but most of services ran are multi threaded, so they are shown on several lines with a % of memory use which in some cases is the same for all, sometimes it varies ...
8
votes
2answers
7k views

ATOP shows red line vmcom and vmlim. What does it mean?

utility atop shows: ATOP - MyServer 2013/01/07 00:03:57 10 seconds elapsed PRC | sys 2.18s | user 8.33s | #proc 141 | #zombie 0 | #exit 0 | CPU | sys 21% | ...
8
votes
1answer
3k views

top / htop; group process by command

I'd like to know how much resource a specific command is using. top and htop displays information on per process basis but I'd like the information to be shown on per command basis. E.g. I'd like to ...
7
votes
1answer
5k views

top output: cpu usage > 100%

Here is the top output which I gathered: I noticed that top is showing vlc's cpu usage is > 100%. Can anybody please justify me why it is showing like this, whether this is a bug in top ...
7
votes
2answers
8k views

Top Command - How to reduce the displayed Columns

Can we get specific column in a top command, for eg I'm interested in only the memory utilization and CPU usage column. How do I reduce the displayed columns of the top command to only the above two ...
7
votes
1answer
27k views

How to check which process is using most memory

When I check free in one of Prod server it showing 70% of memory is being used: total used free shared buffers cached Mem: 164923172 141171860 23751312 ...
7
votes
2answers
7k views

Get CPU utilization stats from C program

I want to read the CPU utilization stats from a C program, I am interested in the percentage of use of CPU, steal time etc. These stats are shown in the 3rd row from the top command. I tried to parse ...
7
votes
1answer
4k views

Why Process CPU % Usage larger than Total CPU Time

When I run the TOP command, a process shows 1208% cpu usage and the total CPU usr time is 81.7% with IRIX mode on. When I change to IRIX mode off, the process shows 99% cpu usage and the total user ...
7
votes
3answers
188 views

How to view summaric memory usage of groups of commands (instead of processes)

Is there a way to group similar processes when using tools like top/htop? Sometimes I just want to know whats eating my memory and some programs (browsers mostly) are using multiple processes, which ...
6
votes
2answers
8k views

How to properly run “top” command through SSH?

I have to run top command on one computer being on another. My targeted PC has IP 192.168.0.81 I was trying to do it: ssh 192.168.0.81 top But I got this result: top: tcgetattr() failed: Invalid ...
6
votes
2answers
16k views

How to see complete list of processes in top

When I do 'top', I learn that there are many processes running out of which many are in sleep state. I need to see complete snapshot of all processes at that point. the 'top' is able to show listing ...
6
votes
2answers
192 views

Why are there so few “running” processes?

On all of BSD/Linux/MacOS and Solaris, I made an observation - no matter how busy the system is, top always reports very few (usually 1-2) running processes. According to my limited understanding, a ...
6
votes
5answers
9k views

Top says 100% CPU used, but 50% of cores idle?

top - 08:43:16 up 96 days, 22:16, 1 user, load average: 4.03, 3.92, 3.98 Tasks: 199 total, 1 running, 198 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 0.5%sy, 50.0%ni, 49.5%id, 0.0%wa, ...
6
votes
4answers
1k views

Full username in top

On our systems user names can be up to 20 characters long. But the top commands only displays the first 8 characters. How can I configure top to display the whole user name? At the moment we use: ...
6
votes
2answers
2k views

Why “uninterruptible sleep” is not counted as “IDLE”?

When I run top -bi, where the parameter -i means "ignore idle processes", the resulted list(see below) of processes are either R or D, although there're S processes at that time. So, why ...
6
votes
2answers
2k views

iotop but for particular disk?

Is there a tool like iotop but for monitoring IO on specific volumes? (Or perhaps I missed a way to filter iotop?) If not is there any way to get at this information via (say)/proc? (dstat etc. ...
5
votes
3answers
3k views

Determining the particular processor on which a process is running

I have access to an 8-core node of a Linux cluster. When logged in to the node, I can see a list of processors using this command: more /proc/cpuinfo In my 8-core node, the processors are numbered ...
5
votes
2answers
2k views

Using top to see processes run by a user on behalf of sudo

If I run top -u username I will see all the processes by a particular user. Is there a way to also see all the processes that the user called via sudo?
5
votes
3answers
227 views

Start top with particular sorting

I'd like to start top with sorting set to resident memory size, instead of the default CPU usage. I don't see a way to do that from command line arguments or startup file. Obviously I can't echo "Oq" ...
5
votes
2answers
1k views

How can we use the command 'top‘ to monitor the total CPU usage and each processor usage simultaneously?

You know that we can use the command top to monitor the real-time CPU usage and toggle the result display to the per-processor view by pressing key 1. The disadvantage of it is you can only monitor ...
5
votes
2answers
1k views

Number of running processes show in top

The usual maximum number that I have seen in the "running" field displayed in top(1) is the number of logical CPUs installed in the system. However, I have observed that under Ubuntu 10.04 (not ...
5
votes
3answers
2k views

How to view a specific process in top

Are there any relatively strightforward options with top to track a specific process? Ideally by identifying the process by a human readable value? e.g. chrome or java. In other words, I want to view ...
5
votes
3answers
911 views

How to freeze current task order?

I believe I have read some time ago how you can make top stop sorting the tasks so that they stay in the same line (easier to read) but still get updates for their values (in contrast to simply ...
5
votes
2answers
3k views

What does it mean exactly when a processes “Time” has stopped in top?

I'll be looking into why we're getting critical swap alerts, and I'll find something like: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ SWAP COMMAND 14683 user1 30 10 16.0g 772m ...
5
votes
2answers
2k views

100.0%sy with poor disk performance

I have RHEL 5.4 kernel 2.6.18-164.el5 and I am experiencing very bad disk performance that happens randomly during working with Oracle. Nothing appears in the logs. When it happens, I see one CPU ...