Open Radar

 
Summary:
Inactive memory can get large, while free memory drops below 100MB. I have 8gb RAM. When new processs/application needs free memory, the system starts to page out, but it doesnt clean inactive memory to get some free space. Te logical step would be that the system dealocates inactive memory (cache), and increases free memory for new process.

Steps to Reproduce:
1. tar (or tar + gzip/bzip2) folder with large amount of data - i tested it with Pictures folder with some 15gb of files, average size 5 mb.
2. watch top, vm_stat, activity monitor --> inactive memory rises up quickly, free memory drops
3. after free memory drops at 100 mb or below, start Safari/iPhoto/MS Word
--
i recorder screen video: 
http://www.youtube.com/watch?v=u5wZwZh61_4&

Expected Results:
System will deallocate inactive memory, and free up memory for new process.

Actual Results:
Safari is starting up more than 1 minute. iPhoto and MS Word aprox same amount of time.
System starts to page out, inactive memory is not cleaned up.
System starts to slow down considerably.

Regression:

Notes:
before starting tar, i have some 5 GB free, and 50 MB inactive memory
the bash command is:
  tar czf tmp.tar.bz2 /Users/emilio/Pictures
or
  tar cf tmp.tar /Users/emilio/Pictures
when system slows down ...