[SOLVED] High CPU load on I/O operation

ack_iix · 08-04-2009, 02:08 AM

Currently I've been using Slackware64-Current since it is first released, and one thing I noticed is file operation (copy, move) from my hard drive (ext4) to external USB drive (NTFS), even copying data from DVD to my hard drive would heavily load my CPU (almost 100%).

I've checked DMA settings, and here's the result:

Code:

/dev/hda:
 multcount     = 16 (on)
 IO_support    =  0 (default)
 unmaskirq     =  0 (off)
 using_dma     =  1 (on)
 keepsettings  =  0 (off)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 16383/255/63, sectors = 156301488, start = 0

Code:

/dev/hdb:
 IO_support    =  0 (default)
 unmaskirq     =  0 (off)
 using_dma     =  1 (on)
 keepsettings  =  0 (off)
 readonly      =  0 (off)
 readahead     = 256 (on)
 HDIO_GETGEO failed: Inappropriate ioctl for device

My machine is using a Intel dual core E2160 clocked at 3 GHz, and file operation putting heavy load on both core is kind of strange.

I'm using stock kernel from Slackware64-Current, anybody using a custom build kernel (2.6.30.x) having this problem? If this problem gone in the new kernel then I'm going to build & install a new kernel.

Thanks.

niels.horn · 08-04-2009, 07:05 PM

The machine I use to test Slackware64 is also a dual core 3GHz box and cpu load is very low...
Just a wild guess: how much memory does your machine have?

Another question: Does this only happen copying to external drives?
Copying on your local drives works w/o problems?

ack_iix · 08-06-2009, 10:26 AM

Thanks for your reply, my machine has 4 GB of RAM, and after more file copy-move testing the highest CPU load occurred when copy or move files to external HDD. Do you ever have similar experience like this?

niels.horn · 08-06-2009, 11:21 AM

Never happened to me...
I use external drives as well, but w/o problems. BTW: I also have 4GB on that machine.

Do you have anything "special" configured, like LVM, software-RAID, encrypted filesystem, etc.?

Is your drive really IDE? (since it is mounted as /dev/hda and not /dev/sda)

disturbed1 · 08-06-2009, 12:23 PM

Quote:

Originally Posted by ack_iix

My machine is using a Intel dual core E2160 clocked at 3 GHz, and file operation putting heavy load on both core is kind of strange.

I'm using stock kernel from Slackware64-Current, anybody using a custom build kernel (2.6.30.x) having this problem? If this problem gone in the new kernel then I'm going to build & install a new kernel.

Thanks.

Check that you are using the correct chipset driver(s) and not generic drivers. Which file system are you using? File systems can cause some overhead, but should not cause 100% spikes.

If you are using the huge kernel, this could be the case. For my systems, using the huge kernel has resulted in using the generic-ide adapter, with ~22 MB/s throughput with 99% CPU. Using the generic kernel with an intrid or compiling my own gives me ~75 MB/s and 2-5% CPU.

ack_iix · 08-06-2009, 05:12 PM

My hard drive is IDE, connected to JMB368 IDE controller on Abit IP35-E mainboard and it's using the pata_jmicron module. All partition is formatted as ext4 and my external USB HDD is formatted with NTFS. I use the generic kernel not the huge one. I've heard rumors about the JMicron controller causing some performance problem, and yes not only the CPU usage is insane, copying lots of file could take very long, which in my opinion indicates low transfer rate.

I've even tried compile a custom 2.6.30.4 kernel based on the config from Slackware64 generic kernel, still no progress though. Please share your advice or experience regarding the JMB368 IDE on Linux.

Thanks.

niels.horn · 08-06-2009, 07:25 PM

Since the high cpu load happens when copying from or to the external drive, let's investigate that.

Check with 'lsusb -v' the information about your external drive and post it here.

disturbed1 · 08-06-2009, 08:52 PM

Quote:

Originally Posted by ack_iix

I've even tried compile a custom 2.6.30.4 kernel based on the config from Slackware64 generic kernel, still no progress though. Please share your advice or experience regarding the JMB368 IDE on Linux.

Thanks.

Code:

03:00.0 IDE interface: JMicron Technologies, Inc. JMB368 IDE controller (prog-if 85 [Master SecO PriO])
Kernel driver in use: pata_jmicron

The driver is provided by libata, and listed as /dev/sd$. If you use the older driver, this controller will be listed as /dev/hd$. I currently have my optical drives connected to this controller - with out using libata burning a disc faster than 8x was not possible, also had high CPU usage. IDE drives connected to this chipset while not using the correct drivers exhibit the same problems you have.

If you compiled your own kernel I'm sure you read this. Why didn't you use the libata driver as suggested?

Quote:

Basic support for the JMicron ATA controllers. For full support
use the libata drivers.

Quote:

Since the high cpu load happens when copying from or to the external drive, let's investigate that.

Check with 'lsusb -v' the information about your external drive and post it here.

Have to agree

If the problem is only with an externel drive. But if you are using a JMicron chipset without the correct drivers, other problems could arise as well.

ack_iix · 08-08-2009, 06:13 AM

Quote:

Originally Posted by disturbed1

The driver is provided by libata, and listed as /dev/sd$. If you use the older driver, this controller will be listed as /dev/hd$. I currently have my optical drives connected to this controller - with out using libata burning a disc faster than 8x was not possible, also had high CPU usage. IDE drives connected to this chipset while not using the correct drivers exhibit the same problems you have.

Thanks for the suggestion, re-compiled my kernel today so the JMicron use the new driver. The drive is recognized as /dev/sda and now my CPU load on copy operation is much better.