drop_caches doesn't drop all caches

10110111 · 11-13-2010, 08:37 AM

I try this command:
$ sudo su -c 'sync && echo 3 > /proc/sys/vm/drop_caches; free'
And here's result:

Code:

             total       used       free     shared    buffers     cached
Mem:       1017108     405280     611828          0          8     183324
-/+ buffers/cache:     221948     795160
Swap:            0          0          0

Why after drop_caches do i still have lots of data cached?

quanta · 11-14-2010, 11:09 AM

As my understand, it is normal. I suggest you open up 2 Terminals, the first one run "watch -n 1 'free -m'" and the second run the "sync && echo 3 > /proc/sys/vm/drop_caches" to see the memory cache from the first down immediately.