Question: I recently upgraded my mid-2011 15” MacBook Pro to Mac OS X 10.9 Mavericks. Since then, my computer’s RAM usage spikes to the point of making my computer unusable. Specifically, anywhere between a minute and 2 hours after booting up, the process `kernel_task` will use between 4 and 5 GB of RAM (I have 8 GB installed) and `mds` and `mds_store` will use around 2 GB between them. At that point all of my apps become unresponsive. 

If I don't restart my computer within about five minutes of this happening, Mac OS X will ask me to quit all of my apps. If I don’t do that the computer becomes totally unresponsive (even to restart requests) and I have to perform a hard shutdown. If I do, the same thing happens but it takes a couple minutes longer. I talked to an Apple representative and he said to flash my PRAM and reset the SMC, which I did, but nothing happened. 

Aside from that he said to send my device in, which I can’t do at the moment. Any idea what's going on?

Answer: 
I posted this question in the Apple support forums [here](https://discussions.apple.com/message/23832367?ac_cid=op123456#23832367) and ran some diagnostics at their suggestion. Since running those, I've discovered a host of new problems with my system that were not present before installing Mavericks. Not the least among them, many of my Python packages no longer work (such as flask and pandas), and `easy_install` and `pip` are now broken. I was recommended to do a clean install (and consider downgrading in the process), which I will do as soon as is convenient.
For me the problem was Adobe Lightroom. I've 18gig of memory on my iMac and the Kernel\_task was taking 5.33 gig. Once I quit Lightroom the memory used dropped to 1.33 gig.

I found the problem app with a:

```
sudo lsof | grep -i kernel

```

Now whose fault is this - Apple or Adobe's?