Question about free/used memory on Linux

!MAILaRCHIVE_VOTE_RePLACE
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Linux Kernel <linux-kernel@...>
Date: Sunday, October 21, 2007 - 1:54 pm

Hi kernel gurus,
I am trying to find out the memory that's used on my linux box.
I find that there are quite a few confusing metrics. How do
I find out the "true" used memory ?

1. For eg. "free -m" shows free memory (excluding buffers/caches) 
as 308 MB while I can see(from "df" output) that the the tmpfs 
partitions take up about 400 MB. So, does "free -m" not consider 
the tmpfs partitions ?

2. I try to add up RSS field of all processes reported by
"ps aux" command. But is it true that this would be misleading
in that, shared memory used by, say 2 processes would show
up twice here although there's only one copy in memory. Also
does this consider the fact that there's only one copy
of shared libraries ?

3. I guess "free -m" and "top" commands use /proc/meminfo 
and hence all these outputs are same ?

Thanks,
Ravi
-
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Sun Oct 21, 1:54 pm)
Re: Question about free/used memory on Linux, Pádraig Brady, (Mon Oct 22, 6:05 am)
RE: Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Mon Oct 22, 9:58 pm)
Re: Question about free/used memory on Linux, Vaidyanathan Srinivasan, (Sun Oct 21, 3:00 pm)
RE: Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Sun Oct 21, 4:21 pm)
RE: Question about free/used memory on Linux, linux-os (Dick Johnson), (Mon Oct 22, 1:34 pm)
Re: Question about free/used memory on Linux, Helge Hafting, (Mon Oct 22, 7:51 am)
Re: Question about free/used memory on Linux, Vaidyanathan Srinivasan, (Mon Oct 22, 1:50 am)
RE: Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Wed Nov 14, 2:14 am)
Re: Question about free/used memory on Linux, Pádraig Brady, (Wed Nov 14, 7:58 am)
RE: Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Wed Nov 14, 2:18 pm)
RE: Question about free/used memory on Linux, Ravinandan Arakali (rarakali)..., (Mon Oct 22, 2:28 am)