'kernel_task' Why does it consume so much memory ?

So lately I've been watching my system processes to see what's been going on under the hood of OS X. One thing I've noticed is that 'kernel_task', when left open (with no other apps running) will eat up more and more physical memory, not just virtual. I left my MBP on last night and this after noon it was taking up about 280 MB of physical memory, which seems rather dubious to me. I had nothing plugged into any of my ports, and was only running the usual which is:

Adium, Lightroom, Firefox and maybe Activity Monitor. But even with those apps totally closed, memory consumption was the same and rising. I restarted my MBP a few hours ago and kernel_task started out at around 68MB. It is currently at 100.5 MB. I've noticed that doing things such as opening apps will increase the number, but shutting them will not decrease it.

So what exactly is going on then ? I ask because I've heard/seen people saying that they leave their computers on for weeks at a time, if not longer. But if this is true, then I'd imagine that the memory usage for kernel_task must be quite large and wonder how it has not affected the performance on their machines. I personally always shut down when I can, but I'm still intrigued by this and can not (in my net searches) find anything but either vague references, or totally geeky explanations that I can not comprehend.

Does anyone think they can explain it in layman's terms ? Also, KT isn't something that can be quit or force quit, and so the only way to reduce its usage is to restart the computer. This is a bit inconvenient. Is there another way to do it ?

cheers.

Doug

Oh yeaaah.. I be bumpin.

Oh yeah I be saying that you should ask Google to be your friend.

I asked google and this popped up.
What Is 'kernel_task' and Why Is It So RAM Hungry? | Second Initial
Kernel_task process taking up an inordinate amount of CPU | MacFixIt - CNET Reviews
And a whole more links.

From what I read you need to look back to System 9. In those days you had an extention manager where you turned on or off verious extensions, and the more extensions you used, the more ram would be used in total obviously.

Fast Forward to today and "kernel_task" is the same thing. It is like the extension manager of OS X. But it's called kernal because all of the extensions reside on the kernal. And this is automated like virtual memory is now also automated in OS X. Kernal_task turns on extensions when it needs them hence it uses more ram. It's ram usage is the total of all the extensions it has turned on and is using at the time.

And to answer your question. I would assume each restart turns off all the extensions. And the extension manager kernal_task just turns them on as it needs them. But I'm not 100% sure it can turn them off without a restart of your computer. So as far as I know the only way to reset this to kernal_task using zero extensions again is to reset the system.

Well you san interchange the words extension and very low level system task right at the heart of your system. Since extensions of the OS 9 sort don't really exist in OS X. But they function in a way like the extensions of old.

Any why people can leave their Macs on for weeks on end is the fact there is only so many of these extensions/tasks in existance to be used by the OS. And I would assume your general usage would affect this too. As the more apps you use, the more system extensions/tasks are needed to be executed by the OS. And they all take up memory. Sure it's only little amounts of memory but it all adds up.

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And you're a little hasty on the bumping yeah .