Memory Mangement Problem in 5.1-RELEASE

Jeremy Messenger mezz7 at
Thu Jul 24 14:06:04 PDT 2003

On Thu, 24 Jul 2003 16:46:12 -0400, Bill Moran <wmoran at> 

> Jeremy Messenger wrote:
>> On Thu, 24 Jul 2003 15:53:21 -0400, Bill Moran 
>> <wmoran at> wrote:
>>> Ahmed Al-Hindawi wrote:
>>>> Hi,
>>>> I have 160Mb of SDRAM (PC100) on a 233Mhz CyrixInstead machine and I
>>>> seem to have memory mangament problems. The BIOS indicates I have 160,
>>>> so does the BSD bootstrap program.
>>>> When I launch GNOME 2.2 everythings is good as gold untill I open the
>>>> System monitor program. It says that I have 149 Mb of RAM which is 
>>>> fine
>>>> ( 4Mb of video..and the rest...god knows).
>>>> I open every program I have and after 107Mb the machine starts to swap
>>>> with about 50Mb left unused!!
>>>> I recompliled the GENERIC kernal for the sake of it really (Im still 
>>>> an
>>>> amature) I didn't mess with the configuration files or anything (I 
>>>> just
>>>> don't know how!!).
>>>> Is this normal or mismanagement of memory in the 5.1 version of the
>>>> excellent FreeBSD kernel??
>>> The mistake is in the way the Gnome System Monitor display the free 
>>> memory.
>>> I just watched both 'top' and the System Monitor as I opened program 
>>> after
>>> program until the system started swapping, and System monitor reports
>>> almost 100M free while top reported less than 10M.
>>> To _always_ have a little memory free is A Good Thing(tm).  FreeBSD has
>>> some pretty advanced memory management that will start swapping 
>>> _before_
>>> the system runs out of RAM.  However, the System Monitor's display of
>>> this is simply inaccurate.  There was NOT 100M free when it started 
>>> swapping
>>> on my system.
>> Well, the 5.0, old -CURRENT and 4.8 have never touch the swap, until 
>> 5.1-CURRENT. My system has 256mb ram and it's always touch swap now. If 
>> I compile some stuff, sometime it will get around 300mb swap. Current, I 
>> only have Gnome 2.3.x and Opera running, so what my top looks like this:
> Well, the old YMMV applies, but I'm not seeing this kind of behaviour.
> I'm also not running 5.1-CURRENT, but 5.1-RELEASE, so it may be a newly
> introduced problem.  The original poster didn't specify whether he was
> using -CURRENT or 5.1-RELEASE.

It's in the subject, he said that he has 5.1-RELEASE. Mine is...

# uname -a
FreeBSD 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Fri Jul 18 
18:43:42 CDT 2003     mezz at  

I am planning to CVSup and do the another update of -CURRENT sometime this 

>> Mem: 85M Active, 29M Inact, 51M Wired, 4496K Cache, 35M Buf, 73M Free
>> Swap: 512M Total, 79M Used, 433M Free, 15% Inuse
> Did something use most of the memory up to start the system swapping?
> If it started using swap while there was still 73M free, then that's new
> to me.

Well, it still should not touch the swap since I have very few stuff 
running with 256mb ram. I just reboot and start with Gnome 2.3.x and Opera, 
then doing the update (compile/install) gnome-panel. Now, it's already use 
the swap in minutes and later hours I will get more mbs or swap.

last pid: 69694;  load averages:  0.30,  0.73,  0.54    up 0+00:26:23  
49 processes:  2 running, 47 sleeping
CPU states: 25.0% user,  0.0% nice,  0.0% system,  0.0% interrupt, 75.0% 
Mem: 123M Active, 21M Inact, 41M Wired, 5776K Cache, 35M Buf, 53M Free
Swap: 512M Total, 3M Used, 512M Free


>> But, I will remove the Gnome System Monitor applet, then reboot and see 
>> how it goes for the whole afternoon.
> I'm not saying that Gnome System Monitor is causing the problem, I'm just
> saying that it reports inaccurate numbers.

-- 's moderator, mezz.

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