Processor Palette color coding
So I'm staring at Tiger's processor palette and find myself wondering what the blue means. Can anyone help me out?
To reproduce: show the palette, reveal the controls (lozenge button on title bar) and make sure 'Detail by Type' and 'Stack' are both checked.
You should see CPU meter(s) with yellow, green, and, occasionally, blue spikes. What do each of these colors represent? I'm pretty certain yellow is the kernel load and green is user space. But what's this elusive blue?
Just curious - many thanks in advance.
-David
To reproduce: show the palette, reveal the controls (lozenge button on title bar) and make sure 'Detail by Type' and 'Stack' are both checked.
You should see CPU meter(s) with yellow, green, and, occasionally, blue spikes. What do each of these colors represent? I'm pretty certain yellow is the kernel load and green is user space. But what's this elusive blue?
Just curious - many thanks in advance.
-David
Comments
Tiger's processor palette
Where? The one in the Activity Monitor doesn't seem to have those controls.
System Prefs > Hardware > Processor, check 'show in menu bar', then click the new menu bar icon and choose 'show processor palette'.
It's pretty nice if you haven't seen it. And, unlike Activity Monitor, it doesn't appear to suck a lot of CPU cycles.
Originally posted by dglow
Sorry, I should clarify. This isn't Activity Monitor, but part of the dev tools; installed with CHUD, I believe.
System Prefs > Hardware > Processor, check 'show in menu bar', then click the new menu bar icon and choose 'show processor palette'.
It's pretty nice if you haven't seen it. And, unlike Activity Monitor, it doesn't appear to suck a lot of CPU cycles.
OK - that is a cool display. I see a blip of blue every few minutes. There is no documentation, but in the Activity Monitor, blue is labeled to mean "%Nice", which means the processes that are running at a lower priority - now exactly what priority "Nice" means is unclear, as you can set the Nice value to whatever you want.
You could test this theory by running a long process using the "nice" BSD command. The "niceness" is from -20 to +20, so positive numbers make the process "more nice", meaning that it runs at a lower priority.
I just tested this theory and it appears that the blue is indeed "nice" processes.
Use my threadedFactorial app with 400 million iterations to see it:
sudo nice -n +20 ~/Desktop/ThreadedFactorial 2 400000000
would set the priority of ThreadedFactorial to +20 (very nice, zero priority), with two threads and 400 million iterations.
The app is at http://www.johnnylundy.com/ThreadedFactorial.zip
EDIT: I found out that if you set it "more nice" (eg +20), it shows as blue; if you set it "less nice" (eg -20) it shows as green, the same as a normal-priority process.