Negative caching

Rashkae ubuntu at
Fri Jun 19 18:16:00 UTC 2009

Rashkae wrote:

> I would counter that running desktop with over 3GB of allocated memory
> on a system with only 1GB of physical ram for weeks before it becomes
> unbearable is a testament to how finely tuned the memory system really
> is.  I notice that not only do you shoot way past my estimate of 2GB,
> but you are flirting with your Commit limit, at which point the kernel
> might start to even refuse further allocation. (Sorry, I forget which
> tunables control this behaviour, but either way, the situation is dire).
>  You'll have to either reduce your memory footprint or add more ram.

Incidentally, if you want to see how much memory is being demanded by
certain applications, /proc/meminfo is a great tool.  Take a look a
Commited_as on a fresh booted system, then after a week, start killing
your app's and at each one, see how much Commited_as was reduced by.  If
there's a memory leak, (and there are probably several, really) you
should see individual applications make a big difference on this value.
 Once all applications have been closed, log out and log back in to
check how much memory your desktop environment uses after a week vs on a
fresh login.  You can use this information to help decide how you tune
your workload to your system specs.

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