Question about disk transfert and CPU

[pmithrandir]

Hi,

I have an "issue" on my computer on cauldron.
When I use the disk, in a copy process for example, the CPU goes immediatly to high level, 80 to 100%.

My computer is not so old to get such result.(athlon 3300+, 1gB of RAM...)
I have the same problem with or without Kdesktop effect.

Do you hav the same issue on your computer ?

The only thing I can imagine different is that I use a raid 0 with my VIA motherboard controller. Mageia use a software to use that. Maybe it could be a reason.

File transfert are arounf 15MB/sec

Thatks,
Pierre

[doktor5000]

Transfer from where to where, and which filesystem(s)?

[pmithrandir]

Finally it's a SIL RAID system.

The problem is from FAT32 to RAID file:///home/pmithrandir/broodwar.nrg EXT 4 and in the other way.

Copy from IDE to RAID is around 24MB/s
RAID 0 to IDE arount 35-40 MB/sec

CPU is at 100% in both case.

When I use diskdrake to check my partition, it takes minutes to open with CPU at 100% (it worked better before, I'm sure of that). I closed it and open it again and it launched normally.

Pierre

[pmithrandir]

Other datas :

When I copy from another computer and Samba to this disk, The CPU is not use anormally.

It seems to occur only when I copy on my computer.

Could it be the copy process binary that do this ? It's the same with cp on console.

[doktor5000]

Transfer from where to where, and which filesystem(s)?

[pmithrandir]

Finally it's a SIL RAID system.

The problem is from FAT32 to RAID EXT 4 and from ext4 to ext 4.

[doktor5000]

Can you copy something that doesn't involve the RAID? Still the high CPU load?

[pmithrandir]

Will do that this evening when I'll be back home

[pmithrandir]

So, my test :

SATA RAID 0 to usb key : 100 % in each way.
USB Key to IDE : 100% too

Any aidea with these results ?

[pmithrandir]

I tried with an old mandriva live release(2008 I think) and I don't go up to 15% of my CPU for the copy...

[doktor5000]

Well, when you used a live, you didn't use the RAID in your current system? That is comparing apples with bananas;)

[pmithrandir]

I tried 2 live system.

The first one was mageia 1 live, and I had the same issue.
The second one was the old mandriva and I got no issue at all.

I have the idea that the raid is involved but I'm not sure. It's just something special in my configuration.
But, on my laptop,(not on caudron) whit a dual core, when I copy something, The CPU is well used. Not at 100%, but maybe aroudn 30 to 50% each. And I have no raid at all.


EDIT :
From my laptop disk to my usb key, for a movie, it took 100% of one CPU, and between 50 and 96% of the other one.
The the other way I was around 80% for one, and 40-50% for the other one.
I disabled the desktop effect before doing the test to prevent any strange stuff.

[doktor5000]

During the copy process, could you open up top and look what uses the most cpu ressources?

[pmithrandir]

The biggest process is kio_file. Around 15%.

Another lead maybe, the hard drives seems to do the same sound than when you write 2 files at the same time, when the disk access 2 place a the same time. (CR CR CR... very fast).

Could it be another process that write all the time on my hard drive ?
I read something also, that ext4 use a lot of disk access because it was writing all the time the access date on the files, so read and write again and again.

[doktor5000]

Could it be another process that write all the time on my hard drive ?
I read something also, that ext4 use a lot of disk access because it was writing all the time the access date on the files, so read and write again and again.

Well for the first, you can check that with iotop.
For the second, no, as Mageia defaults to use the noatime flag when mounting Mageia-created partitions.
You can check that in /etc/fstab.

[pmithrandir]

HI,

So I got kio file, and kio thumbmail when I copy something working at the same time(it seems that KDE try to read the video, before it's copied.

Otherwise, here is my fstab :

Code: Select all

/dev/mapper/sil_bhadaedeccdip6 / ext4 defaults 1 1
/dev/mapper/sil_bhadaedeccdip5 /boot ext4 defaults 1 2
/dev/mapper/sil_bhadaedeccdip10 /home ext4 defaults 1 2
/dev/mapper/sil_bhadaedeccdip11 /mnt/datas ext4 defaults 1 2
# Entry for /dev/sdc1 :
UUID=07FA-1F14 /mnt/windows vfat defaults,umask=000 0 0
none /proc proc defaults 0 0
/dev/mapper/sil_bhadaedeccdip9 /tmp ext4 defaults 1 2
/dev/mapper/sil_bhadaedeccdip8 /usr ext4 defaults 1 2
/dev/mapper/sil_bhadaedeccdip7 /var ext4 defaults 1 2
/dev/mapper/sil_bhadaedeccdip1 swap swap defaults 0 0


[pmithrandir]

Hi,

I put noatime in fstab on all my partition(from MCC partition manager)

Now it's like that :

Code: Select all

/dev/mapper/sil_bhadaedeccdip6 / ext4 noatime 1 1
/dev/mapper/sil_bhadaedeccdip5 /boot ext4 noatime 1 2
/dev/mapper/sil_bhadaedeccdip10 /home ext4 noatime 1 2
/dev/mapper/sil_bhadaedeccdip11 /mnt/datas ext4 noatime 1 2
# Entry for /dev/sdc1 :
UUID=07FA-1F14 /mnt/windows vfat umask=000,noatime 0 0
none /proc proc defaults 0 0
/dev/mapper/sil_bhadaedeccdip9 /tmp ext4 noatime 1 2
/dev/mapper/sil_bhadaedeccdip8 /usr ext4 noatime 1 2
/dev/mapper/sil_bhadaedeccdip7 /var ext4 noatime 1 2
/dev/mapper/sil_bhadaedeccdip1 swap swap defaults 0 0


But, still at 100% of my CPU

[doktor5000]

Does this also happen when you copy from the command line, or without graphical environment started, i.e. in failsafe mode?

[pmithrandir]

Hi.

I tried what you ask, and somthing else.

Results : (same files)
->failsafe : copy process arount 15-20%
->console(CTRL ALT F1) : cp process arount 20-25% (with X started), KDE CPU plasmoid monitor say 100%.

I saw something strange. During cp process, the system use arount 100MB of the swap, even if I have 600MB of free RAM.
I tried to unmount the swap and the disk make less noise(the CRR CRR CRRR of the disk). But the CPU is at 100% in KDE CPU plasmoid monitor.

Do you knwo why the system use swap ?

Any other idea ?
Thanks for your time. It pleasant to get some help.

Pierre

[doktor5000]

Don't know really for the swap. When you run a terminal under KDE, and copy there with cp or midnight commander, still the high cpu load?
Also you actually don't have free RAM, as linux takes up everything. And big copy operations also needs some cache. You know - free RAM is unused/wasted RAM