RE: 2.4.1 eats RAM or /proc/meminfo bug

[Ricardo Galli]

> you should give up thinking there's any real relation between 2.2
> and 2.4.  yes, they're both Linux, but their behaviors are essentially
> unrelated.
>
> >              total       used       free     shared    buffers
>    cached
> > Mem:        255340     232444      22896          0      16988
>     93212
> > -/+ buffers/cache:     122244     133096
> > Swap:       208804          0     208804
>
> no swap in use, so there's no problem.  except that 22MB is free/wasted.

Then, who is using those 122,244 KB of RAM than cannot be otherwise used for
buffers/cache?

Perhaps I am wrong and that number is the sum of procs memory plus
buffer/caches, but then it should have more free RAM than show in
free/meminfo. And altough cache and buffers are more or less stable, the
reported "used" memory" is still increasing.

What I understand is (no accounting for swap):

cache+buffers == active+inact_dirty+inact_clean.
userland mem == total - (kernel + cache + buffers)

but my reported numbers don't match. I am doing against the maths with the
current situation, and they still worse, buffers/cache have increased in
~4MB but free memory has decreased in ~14MB (with the same workload and
processes):

[gallir@m3d gallir]$ free
             total       used       free     shared    buffers     cached
Mem:        255340     246816       8524          0       4048     110736
-/+ buffers/cache:     132032     123308
Swap:       208804          0     208804

It's preferable to use all available RAM for buffers/cache, but this isn't
the case...

Sorry if I am wrong, I couldn't find more related docs about these changes.

--ricardo