set a limit for the cache

set a limit for the cache

[Kappl, Hannes]

 Hi,

 I am using kernel 2.4.4. I have 32M RAM with a 10M Ramdisk. Now my problem is
that
 the Ramdisk is cached in the RAM(4 - 8M!). Is it possible to set the size of
the
 cache to a limit or to disable the cache complete?



   7:13pm  up 34 min,  0 users,  load average: 0.12, 0.33, 0.30
 22 processes: 21 sleeping, 1 running, 0 zombie, 0 stopped
 CPU states:  0.9% user,  4.3% system,  0.0% nice, 94.7% idle
 Mem:   30612K av,   9216K used,  21396K free,   9904K shrd,      0K buff
 Swap:      0K av,      0K used,      0K free                  5392K cached

  PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
  107 root      14   0   836  836   644 R       0  4.5  2.7   0:00 top


 best regard
 Hannes


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Re: set a limit for the cache

[Alex Zeffertt]

Kappl, Hannes wrote:

>  Hi,
>
>  I am using kernel 2.4.4. I have 32M RAM with a 10M Ramdisk. Now my problem is
> that
>  the Ramdisk is cached in the RAM(4 - 8M!). Is it possible to set the size of
> the
>  cache to a limit or to disable the cache complete?
>
>
>
>    7:13pm  up 34 min,  0 users,  load average: 0.12, 0.33, 0.30
>  22 processes: 21 sleeping, 1 running, 0 zombie, 0 stopped
>  CPU states:  0.9% user,  4.3% system,  0.0% nice, 94.7% idle
>  Mem:   30612K av,   9216K used,  21396K free,   9904K shrd,      0K buff
>  Swap:      0K av,      0K used,      0K free                  5392K cached
>
>   PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
>   107 root      14   0   836  836   644 R       0  4.5  2.7   0:00 top
>



I'm confused, top says that you have 21.4M free.  If your 10M ramdisk was being cached in 4M of RAM
then surely you'd have at most (32-14)=18M free?

While we're on the topic of RAM usage, can anyone tell me how you find out how the shrd memory (see
top output above) is broken down into seperate libraries.

Thanks,

Alex

>
>  best regard
>  Hannes
>
>
>
>


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Re: set a limit for the cache

[Conn Clark]

You can do this by changing values in the /proc file system.
Refer to the docs in the kernel source.

"Kappl, Hannes" wrote:
>
>  Hi,
>
>  I am using kernel 2.4.4. I have 32M RAM with a 10M Ramdisk. Now my problem is
> that
>  the Ramdisk is cached in the RAM(4 - 8M!). Is it possible to set the size of
> the
>  cache to a limit or to disable the cache complete?
>
>    7:13pm  up 34 min,  0 users,  load average: 0.12, 0.33, 0.30
>  22 processes: 21 sleeping, 1 running, 0 zombie, 0 stopped
>  CPU states:  0.9% user,  4.3% system,  0.0% nice, 94.7% idle
>  Mem:   30612K av,   9216K used,  21396K free,   9904K shrd,      0K buff
>  Swap:      0K av,      0K used,      0K free                  5392K cached
>
>   PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
>   107 root      14   0   836  836   644 R       0  4.5  2.7   0:00 top
>
>  best regard
>  Hannes
>

--

*****************************************************************
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 (Warning they may try to sell their house out from under you.)
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Conn Clark
Engineering Stooge				clark@esteem.com
Electronic Systems Technology Inc.		www.esteem.com


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