General :: 'clear Out' All The Old/cached Crap From RAM/SWAP To Free Up Space?

Closest analogy I can compare what I want to, is like the `sync` command, which writes out all stuff in the disk buffers, freeing the buffers.Instead of disk buffers, I want to 'clean out' my RAM and SWAP of any/all junk that's accumulated in there over the time my PC has been up. I've long wondered about this, but never asked, though I recall searching around several times..When I first boot it cold and log in, the memory usage bar on my desktop is near zero, and the swap is empty. But after a week or 2 or 3 or more of uptime, and with Firefox always running with a dozen tabs or so at any given time, I end up with all the memory full or 'filled with cached stuff', and the swap space is filled to capacity.Curiousity: I blame Firefox for leaking memory, but even if that's still the case today (historically it was) can this all be blamed on Firefox? Or what-all causes this, besides Firefox- just..Everything?

Here's current stats:

Code:

sasha@reactor: uptime
21:21:42 up 30 days, 10:07, 3 users, load average: 0.02, 0.05, 0.01
sasha@reactor: free
total used free shared buffers cached

[code]...

So, 3.8 of 4 Gib of RAM is occupied, and the 1 Gib swap space is jammed full 100%. This must slow things down to some degree, yes? I mean, the kernel does have to keep track of this, right?Of course closing all the applications doesn't make a difference (not an appreciable one anyhow) and the only way I have found to start fresh is to reboot.