Re: need help interpreting 'free' output.

Hugh Dickins
2001-10-30T16:05:43Z

On Tue, 30 Oct 2001, Frank Dekervel wrote:
>
> since i saw strange things happening with my free memory numbers, i tried
> this:
> - i compiled and booted a fresh kernel (no proprietary modules, no patches,
> just 2.4.14-pre4)
> - i did free.
>
> bakvis:~# free
> total used free shared buffers cached
> Mem: 384912 55644 329268 0 3652 29880
> -/+ buffers/cache: 22112 362800
> Swap: 136512 0 136512
>
> so i have 22 meg used right ?
>
> - i started the daily cron jobs (updatedb and htdig and some minor things
> like log rotation)
>
> - i did 'free' again.
>
> bakvis:~# free
> total used free shared buffers cached
> Mem: 384912 377060 7852 0 29424 125660
> -/+ buffers/cache: 221976 162936
> Swap: 136512 752 135760
>
> so now there is 220 meg used memory right ?
> and the memory is definitely used, because as soon as i start a memory hog
> the system hits swap ...
>
> so what am i missing here ?
> should i provide more info about my kernel configuration ? vmstat numbers ?

I'm fairly sure /proc/slabinfo will show large inode_cache and large
dentry_cache: which is natural after updatedb, nothing wrong with that.

However, unlike 2.4.13, 2.4.14-pre (you tried pre4, I just tried pre5)
seems much too unwilling to shrink_dcache and shrink_icache: your
memory hog should shrink them, but it seems not to. Linus?

Hugh