Linux – how to *start* a process with a high priority

As of GNU coreutils 7.5 released in August 2009, sort allows a -h parameter, which allows numeric suffixes of the kind produced by du -h:

du -hs * | sort -h

If you are using a sort that does not support -h, you can install GNU Coreutils. E.g. on an older Mac OS X:

brew install coreutils
du -hs * | gsort -h

From sort manual:

-h, --human-numeric-sort compare human readable numbers (e.g., 2K 1G)

I'd highly suggest not doing this. If your server is so heavily loaded that apache isn't getting the CPU time it needs, then renicing a process will have a very minimal effect, if any. Additionally, apache will have many different processes running at any one time. You could renice the parent process, and its children will inherit the parent's niceness, but then all of the httpd processes will be fighting each other for time.

In old kernels (say late 90s/early 00s), I found there to be some value in renicing processes (though I usually only decreased priority, not increased). With the scheduler in modern kernels, I've never found it to be necessary or even worthwhile thinking about.

In conclusion, to solve performance problems, there are a plethora of other areas I would pay attention to before I'd start blaming process priority.