I have a homebuild computer with red hat 9.0
cpu: athlon 2500+
ram: 1GB DDR2700
swap: 1GB
IN linux, as long as i don't move big files around. It runs fine.
when i move a bunch of stuff which weight around 1GB, my computer's performance become sluggish.
even my mouse don't even move right.
the problem is every time i move something, my memory become 99.9% in use.
swap only used around 800KB?
what's wrong here?

Hiya,

Open a terminal and run top. Move something to cuse the problem again, and post back what top was displaying


Druisgod

I had a similar problem before, where the issue was the hard drive settings. Look up the hdparm command and all of the options that go with it, you should be able to enable DMA (if it isn't already enabled) and increase performance significantly.

Try this perhaps:
http://www.linuxdevcenter.com/pub/a/...29/hdparm.html

i am not experience sluggish performance becasue of the hard drive.
the problem is why is linux sucking up all my memory.

i will do the top thing right away when i got my hands on my linux box

Ok. If you run top, we might be able to find out what app, if it is an app, that is causing your issue.


Druisgod

here are the output when i run top while transfering 3 mandrake isos
memory running 99.9%


20:29:12 up 27 min, 4 users, load average: 1.59, 1.40, 0.89
86 processes: 82 sleeping, 4 running, 0 zombie, 0 stopped
CPU states: 9.1% user 21.5% system 0.0% nice 0.0% iowait 69.2% idle
Mem: 1032100k av, 1016488k used, 15612k free, 0k shrd, 19440k buff
198288k active, 696516k inactive
Swap: 1052216k av, 0k used, 1052216k free 778944k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND
6052 malibu 14 0 6128 6124 5096 S 16.5 0.5 3:45 0 magicdev
6077 malibu 10 0 11028 10M 7152 R 5.7 1.0 0:03 0 gnome-terminal
5970 root 12 0 32824 23M 2784 S 3.7 2.2 0:58 0 X
6249 root 10 0 20680 20M 10680 S 2.5 2.0 0:25 0 nautilus
1 root 8 0 464 464 416 S 0.0 0.0 0:04 0 init
2 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 keventd
3 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 kapmd
4 root 19 19 0 0 0 SWN 0.0 0.0 0:00 0 ksoftirqd_CPU0
5 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 kswapd
6 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 bdflush
7 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 kupdated
15 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 kjournald
74 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 khubd
3913 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 kjournald
5384 root 9 0 0 0 0 SW 0.0 0.0 0:00 0 knodemgrd_0
5667 root 9 0 580 580 500 S 0.0 0.0 0:00 0 syslogd
5671 root 9 0 428 428 376 S 0.0 0.0 0:00 0 klogd
5722 root 8 0 484 484 436 S 0.0 0.0 0:00 0 apmd
5758 root 9 0 1512 1512 1272 S 0.0 0.1 0:00 0 sshd
5772 root 9 0 932 932 804 S 0.0 0.0 0:00 0 xinetd
5782 root 9 0 444 444 396 S 0.0 0.0 0:00 0 gpm
5791 root 9 0 572 572 508 S 0.0 0.0 0:00 0 crond
5802 root 9 0 2020 2020 1476 S 0.0 0.1 0:00 0 cupsd
5866 xfs 9 0 3120 3120 808 S 0.0 0.3 0:00 0 xfs
5875 root 8 0 2036 2036 1424 S 0.0 0.1 0:00 0 smbd
5879 root 9 0 1812 1812 1248 S 0.0 0.1 0:00 0 nmbd
5888 root 19 19 616 616 536 S N 0.0 0.0 0:00 0 anacron

AS others have said, check your dma on the drives. linux always uses all memory. The lack of dma controller will cause sluggish PC on large file transfer. Show the hdparm -d output on the drive(s)... also show the results of free to see what memory is actually tied up in processes.

it will try "free" asap.
i am sure my dma is enabled because when it's not.
hdparm -Tt /dev/hda doesn't go up to 50mb/s.
but what is free for?

It seems to show how much memory and swap are being used at the time.

hey-
i may be missing the point, and am admittedly new to Linux, but from what little i understand, Linux uses memory totally different from Windows. In windows, it is abnormal to have that much memory use, but in Linux, the theory is "Unused memory is not good use of memory." Is it just the numbers that are buggin you, or is everything really running slow? I had the same question when i first started using it, because my memory usage was always high.

Thanks for clarifying.

-myk

yes, it is bothering me.
because whenever that happens, my cursor doesn't even move smooth anymore!
application runs really slow.

Why we ask about the dma is because this is a symptom of no dma - the jerky cursor, sluggishness etc. The hdparm test makes it sound like it's working, but a result of

hdparm -d /dev/hda

would make us feel better.

also the results of the command

free

would tell us how much memory is actually used and how much is just being used as cache an buffers. Linux doesn't waste memory. If apps aren't using the memory, linux will just use it for cache and buffers. You paid for it, so why not use it...

Also what cpu are you using, just out of curiousity?

He stated above that he is running an athlon 2500+

I agree with many of the posts above. Having 90+% of your memory in use is not a bad thing...it shows your memory is being used efficiently. I think that if you run the free command (use free -m for output in MB) you will find that 50-60% is being used as cache.

I am pretty sure that your problem is from a disk i/o logjam, especially since you don't have this problem unless moving large files around. Running hdparm /dev/hda will show if you are using DMA and other options to speed up disk thruput such as multcount, 32-bit IO_support, and readahead.

# hdparm -tT /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 0.32 seconds =400.00 MB/sec
Timing buffered disk reads: 64 MB in 1.13 seconds = 56.64 MB/sec

# hdparm /dev/hda

/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 14946/255/63, sectors = 240121728, start = 0

# hdparm -d /dev/hda

/dev/hda:
using_dma = 1 (on)


because i don't really have time right now, i will post the free -m tomorrow when i get my linux drunk again! with full memory

That's good. Knowing that dma is on eliminates that so we can look further.