Recent performance issues.

[Guest]

Some time in the last week or so my computer started behaving very poorly after being on for a while. (< day that is).

It seems like a leakage of resources somewhere that is only solved by rebooting. It reaches a point where new processes cannot be started and it complains that KLauncher is not running anymore.

When it's like that and I run free I am typically getting something like this...

nev@bananinha:~$ free
total used free shared buffers cached
Mem: 1017392 983048 34344 0 25572 511980
-/+ buffers/cache: 445496 571896
Swap: 2047992 19204 2028788
nev@bananinha:~$

Nearly a GB of real memory used, and all I'm running is Firefox, one Konsole, System Monitor, qbittorent, pidgeon, and wicd.

What I don't understand is that System Monitor says that only 0.44 GB is in use, which seems a lot more reasonable.

What does this mean?

[HERE I REBOOT]

After rebooting and all the same stuff running free says...

nev@bananinha:~$ free
total used free shared buffers cached
Mem: 1017392 688848 328544 0 22664 252732
-/+ buffers/cache: 413452 603940
Swap: 2047992 0 2047992
nev@bananinha:~$

and System Monitor says that 0.40 GB is in use. Still a big discrepancy, though 300MB lower memory usage.

Can anyone advise what's making it, and what tools can I use to track down where the difference is being used?

Also of course is the issue that the performance goes down the toilet when it's barely even touched the swap.

I have 9.04 with all the latest updates, except that I'm using the 2.4 intel driver (I had this for a couple of weeks with greatly improved performance over the newer one for two or three weeks before the latest issues).

Cheers,

N

[jankushka]

Re: Recent performance issues.

hi.

The inner workings of the Linux virtual memory subsystem are quite complex...

i'll try to keep this very simple.
gnu/linux tries to exploit physical memory as much as possible.
so, when you start an application and then close it, that application is not physically removed from memory.
in case you wanted to start that application again, it will already be in memory and start a lot quicker.
that doesn't mean that memory is unavailable to other applications.
if something else claims (all or part of) that memory, that memoy will obviously be made available.
when you have your system up and running for some time and you run "free", you will almost certainly see all of your memory used.
from the figure you see under "used" you will however have to subtract the figure under "cached".
that will give you the memory that is actually used and cannot be freed unless you close something.

now to your problem...
running out of physical memory does not necessarily prevent new processing from starting.
the gnu/linux virtual memory system includes disk (swap) space to act as memory.
you have 1gb of ram and 2gb of swap.
that makes your system a 3gb virtual memory system.
memory is not the cause of your problem.

system disk space may be.
check the disk space availble in the file system that includes the /var directory.
that normally is the / (i.e. root) file system.
if your system cannot write in there (because you've run out of space), then new processes cannot be started.
no matter how much physical or virtual memory you have.

hth