renice command increasement by 5

dolios

on Knowledge Check Question 3.2 it wants to increase the niceness by 5. But none of the below seems to do it?

[root@localhost ~]# renice 5 28977
28977 (process ID) old priority 5, new priority 5

[root@localhost ~]# renice +5 28977
28977 (process ID) old priority 5, new priority 5

dolios

Right both set it to 5 since 5 and +5 are both positives. But the question is only valid if the niceness is 0 although that is not mentioned. "Question 3.2
Which command will increase the niceness by 5 units of the process with PID = 444?" not set it to 5. Or am I miss understanding something?

Is there a command for a general increase of niceness independent of what it currently is or do you first need to know what it is and then have it increased by 5. (renice +5. renice +10, renice +15)

luisviveropena

Hi @dolios ,

on Knowledge Check Question 3.2 it wants to increase the niceness by 5.
But none of the below seems to do it?

I think the question should be "setup" instead "increase". I'll check it with Coop.

Is there a command for a general increase of niceness independent of what
it currently is or do you first need to know what it is and then have it increased by 5.
(renice +5. renice +10, renice +15)

As far as I understand, "renice" is to setup a new niceness value for a running process. And "nice" is to start a process with a specific "niceness".

The good thing is that you can see it for yourself in a small test (I just did it):

1.- Start an application, let's say firefox.
2.- See the pid of the process, using "ps -fe | grep firefox" or "top".
3.- Run top with the pid, for example:

top -p 3967

Where 3967 is the pid for firefox (the parent process) on my system.

4.- In another terminal do tests using "renice". For example:

renice 10 3967

And see what happens in the top output.

I hope that helps to clarify the use of nice and renice.

I'll check anyway the KC for this chapter.

Many regards,
Luis.

coop

This error should have been fixed months ago but seems to have fallen through the cracks. It should say "set " not "increase". It will be fixed in next update.

akamch

There is the same problem with the language on the page "Modifying the Nice Value" in module 3:

To raise the niceness of an already running process, it is easy to use the renice command, as in:

$ renice +3 13848

which will raise the nice value by 3 points for the process with pid = 13848.

In this case "raise the nice value by 3 points" sounds wrong for any process with a non-zero niceness before renice.

luisviveropena

Hi @akamch ,

Thanks for the catch.

Regards,
Luis.

chuckdsk

"Question 3.2
Which command will set the niceness to 5 units of the process with PID = 444? Select all answers that apply.

A. renice 5 444
B. renice +5 444
C. nice -5 444
D. nice +5 444"

As far as I can see, both A and B are correct (tested with sleep 100 & and used both commands with the pid of sleep--both worked).

When I select A, the results show that B is the correct answer.

When I retake the quiz and select B, the results show that A is the correct answer.

I feel that the instructional content for both nice and renice is not clear at all, particularly regarding + and no +.

Moreover, the man page for renice is a pile of hot garbage, as it only mentions + as an example and does not detail it in the OPTIONS section.

While I learned a lot about nice, renice, and ps (an even bigger pile of hot garbage), trying to figure out what was going on here, I recommend a review of this section of the course materials with an eye towards tightening up clarity a bit.

Thanks!

beraldo.felipe

@chuckdsk Thats because both of them are correct!