Tag Info

Hot answers tagged

14

Since linux 2.6.12, that depends on the value of the RLIMIT_NICE limit (ulimit -e). Which can take values from 0 to 40. That limit is more the limit on the priority of the process (the greater that number, the higher the priority a user can set for a process). You'll notice the default value is 20 on ubuntu 10.04 and 0 in Debian jessie for instance. A ...


14

It's for what I'd call policy reasons. The idea is that normal users can't override the actions of privileged users. Let's say you're a user on some enormous shared server. You're running monstrous CPU-hogging processes to the detriment of the other users. The sysadmin renices some of your processes because he doesn't like you very much. The OS doesn't ...


5

renice does affect the priority of a process. But as you've experienced, just because a process has higher priority doesn't imply that it will have all the resources it needs. A higher priority merely gives the process a bigger chance to grab resources. renice only affects CPU time. So it only has an effect if two or more processes are competing for CPU ...


1

Process priority is not the only thing that comes into play when you are trying to tweak user experience. Compiling the kernel is a rather I/O-heavy thing - lots of reading/writing from/to small files which can stretch the file system quite a bit (there is a reason why it is sometimes used as a benchmark in its own right), especially on a multiprocessor ...


1

In fact, RLIMIT_NICE allows you to bypass the basic rule that says that "a process can raise its nice value only if owned by root". Demonstration: # ulimit -e 30 # su nobody $ nice -n -10 top You will see that your top process runs with niceness -10. Now if you try nice -n -11 top, it will run with niceness 0, because -11 is not allowed by ...



Only top voted, non community-wiki answers of a minimum length are eligible