Meaning of "cached" when top utility is run

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When I run top, I see:

Mem: 27072K used, 100256K free, 0K shrd, 0K buff, 10584K cached
Load average: 0.33, 0.25, 0.21    (State: S=sleeping R=running,
W=waiting)

What does "10584K cached" mean?  My system crashes once I get above
12000K cached.  Is there a configuration variable I can change
somewhere to stop it from crashing when cached reaches 12000K?

I am running Linux 2.6.10 on powerpc.

Re: Meaning of "cached" when top utility is run
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That might not be a stable kernel. In debian we used 2.6.8 and then
pretty quickly went to 2.6.18 and now in the 20s. There was a major
transition between 2.6.15 and 2.6.18.

You should try a recent kernel.

What model machine do you have and what processor ? Are you
sure all your RAM is really good ? You could try moving/removing a
card.
Small RAM modules are sometimes not tolerated well anymore (small
means 16-32MB) -- if you have any of these best to try taking
them out if you are having crashes.

That's about all I can say unless you tell me the particular machine
and date/version/name of your distribution.

Re: Meaning of "cached" when top utility is run
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It's a custom board with 128 MB of RAM and an MPC8248 processor.
Others have said to try a recent kernel.  Do you have a specific
reason why a newer kernel will fix the problem?

Re: Meaning of "cached" when top utility is run
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It is always best to use the latest version, because of various bugs
being fixed.
Anyway, he said you should try - not that it is going to fix your
problem. It might be something else

Re: Meaning of "cached" when top utility is run
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I don't think 2.6.10 was a stable kernel, unless the manufacturer
supplied it but even then it does not look good to me. Its probably
just so you can test it and know it more or less works.

depending on whether you have upgraded any other software
on it then things could really be broken.

If you install a stable release and you find stuff like this happening
then if I were you I would contact the manufacturer. May be
there is a hardware problem, but as I said before check that
your RAM is not defective !

Maybe there are kernel parameters to fix the cache size, but
since that was experimental in 2.6.10, you really should get
a newer kernel. Then go to some kernel gurus and ask them
about setting it dynamically, if you must. But it is not so
good an idea, it will slow it down badly.


Re: Meaning of "cached" when top utility is run
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Sorry, to answer your question: cached/buffers means memory that
is used to save on disk-i/o I believe. To be able to reuse libraries
rather
than reread them is much faster. Also not to write to disk right away.
Perhaps too some video buffer if you are low on video memory.

Usually the devices can be told to read/write from/to a memory space
and the cpu can go along its business if it can.

Re: Meaning of "cached" when top utility is run
Also the size of the shared memory (ipcs -m)  is included into the cached
number.

Regards,

Sani



Quoted text here. Click to load it

Sorry, to answer your question: cached/buffers means memory that
is used to save on disk-i/o I believe. To be able to reuse libraries
rather
than reread them is much faster. Also not to write to disk right away.
Perhaps too some video buffer if you are low on video memory.

Usually the devices can be told to read/write from/to a memory space
and the cpu can go along its business if it can.


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