Cache Memory in top command

Bas Smeelen b.smeelen at
Thu Sep 30 07:25:00 UTC 2010

On 09/29/2010 07:36 PM, RW wrote:
>>> Bas Smeelen <b.smeelen at> wrote:
>>>>  *Cache:* number of clean pages caching data that are available for
>>>> immediate reallocation
> I don't see why it would be included in wired, and I'm pretty sure
> that's wrong. 
>From the man page:

*Wired:* number of pages wired down, including cached file data pages

> The cache queue is a stock of clean pages, it's sort of an intermediate
> state between inactive and free. Most memory allocations can be
> performed directly from the cache queue, which allows memory to hold
> useful data right up to the moment it's reallocated, and it allows
> FreeBSD to run with very little free (i.e. wasted) memory.
> Cache memory is topped-up with memory from the inactive queue in the
> background. Likewise inactive memory is topped-up from active memory.
> Since that's done on demand the values are virtually meaningless. 
Thanks for your detailed explanation

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