Re: VM - a plenty of inactive memory

From: Johannes Weiner
Date: Wed Apr 09 2008 - 09:11:25 EST


Hi,

"Andreas Grimm" <agrimm61@xxxxxxxxx> writes:

> Hello everybody,
>
> i got a weird problem with one of my servers. It's a Intel SR2500AL
> with 32GB of RAM.
> Looking at the memory usage of the system, something is going totally
> wrong. The crucial numbers from /proc/meminfo are:
>
> MemTotal: 33265916 kB
> MemFree: 416168 kB
> Inactive: 24630428 kB (24GB? whooaaa)
>
> Another system with only 16GB, same amount of users and load, shows a
> more normal behaviour:
>
> MemTotal: 16619808 kB
> MemFree: 6912676 kB
> Inactive: 1774364 kB
>
> Why does the 32GB-System have this plenty of inactive memory. Is there
> a way to find out, what the kernel is holding in readiness (that's the
> definition of inactive memory afaik)?

Inactive pages are marked in use but haven't been touched for some time.
These are candidates for memory reclaiming.

If nothing memory consuming happens, the kswapd should reclaim them back
eventually.

Hannes
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