Re: Free memory, include "cached"?

[Gilles Chanteperdrix <gilles.chanteperdrix@xxxxxxxxxxx>]

Matthias Kaehlcke wrote:
> El Tue, Oct 14, 2008 at 03:03:27PM +0200 Gilles Chanteperdrix ha dit:
> 
>> Gregoire Banderet wrote:
>>> Matthias Kaehlcke wrote:
>>>> El Tue, Oct 14, 2008 at 02:14:46PM +0200 Gregoire Banderet ha dit:
>>>>
>>>>> anubhav rakshit wrote:
>>>>>>> I have to report the amount of FreeMem on my embedded system. The rootfs
>>>>>>> is in RAM. I use /proc/meminfo.
>>>>>>> I started by doing : freemem = MemFree + Buffers + Cached
>>>>>>> But I realized (tell me if I'm wrong) that my rootfs filesystems is
>>>>>>> counted in "Cached".
>>>>>>> Part of the memory in "Cached" can be allocated, so I should add it as
>>>>>>> Free Memory, but part of it is my rootfs (i.e. really used).
>>>>>>> How should I compute freemem ?
>>>>>> Have you tried the free command.
>>>>> Yes. What I need is to know which part of "Cached" is used for RAMFS.
>>>> to know the size of your ramfs you may execute the following command:
>>>>
>>>> du -hx -d 0 /
>> If you want to get the space occupied on a partition, you should use df,
>> not du.
> 
> depends on the type of the partition. df doesn't work with initramfs,
> i suppose the reason is that an initramfs image has no partition size,
> so it doesn't make sense to report free disk space.

Are you talking about tmpfs or about cramfs ? A mounted tmpfs has a
maximum size, and df correctly reports the free and occupied size. A
cramfs filesystem is a read-only filesystem, so df correctly reports 0
as the free size, and also reports correctly the occupied size.

So, I really do not understand what you are saying.

-- 
                                                 Gilles.

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