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I found memory usage is so high.
And i checked it via top command, only 66664k free, my computer's total memory is 12GB.
I checked all processes via system monitor software, found all processes cost about 200MB memory.

  1. Why does top command say only 60kb memory is free?

  2. Sometimes, i found some processes cost memory about 10TB and they free the memory at once. anybody tell me? thanks.

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migrated from Nov 29 '12 at 13:22

This question came from our site for professional and enthusiast programmers.

If you Google this, you'll find about a million hits as to how Linux uses memory. – Nikos C. Nov 29 '12 at 9:38
Unused memory is pretty much wasted. Preloading, Caching etc. will use RAM while other processes don´t. – ThomasS Nov 29 '12 at 11:46

The short answer is — cache. Don't worry too much, used memory means it's not just collecting dust. It still can be used for other purposes, though.

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but my workstation is so slow that i have to restart it. – ken Nov 30 '12 at 6:25

Have you tried with htop?

To install on a Debian-based system:
apt-get install htop

1. Green = Used Memory
2. Blue = Buffers
3. Yellow = Cache

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+1 for bringing htop to my attention. It's pretty sweet! – Ian Atkin Nov 29 '12 at 21:00

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