ksoftirqd

[Krister]

I'm having trouble with ksoftirqd which is taking 25% CPU on my B2 and slowing down the system. Rebooting does not help.

Does anyone know why it takes 25% CPU?

//Krister

[Cheeseboy]

Hi Krister,

Have you got any hardware attached to your Bubba?
Have a look at this:
http://www.tin.org/bin/man.cgi?section= ... =ksoftirqd

Perhaps you could ask Ubi if you could join the Munin club? That will give you better stats, even if they are sometimes mysterious....

Cheers,

Cheeseboy

[willem2]

On my BubbaTwo the CPU time from ksoftirqd is ath9k (atheros wifi) related.
You can check with:

Code: Select all

cat /proc/interrupts

results after 6 days uptime:

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          CPU0       
 16:       4250   IPIC   Level     serial
 18: 3273180484   IPIC   Level     ath9k
 19:          0   IPIC   Level     mpc8xxx_spi
 20:    1252900   IPIC   Level     sata_sil
 21:          0   IPIC   Level     phy_interrupt
 22:       1371   IPIC   Level     i2c-mpc
 23:          0   IPIC   Level     i2c-mpc
 24:          0   IPIC   Level     talitos
 32:    1453346   IPIC   Level     eth0_tx
 33:    2187563   IPIC   Level     eth0_rx
 34:          0   IPIC   Level     eth0_er
 35:     744666   IPIC   Level     eth1_tx
 36:     587431   IPIC   Level     eth1_rx
 37:          0   IPIC   Level     eth1_er
 38:         43   IPIC   Level     ehci_hcd:usb1
 48:          0   IPIC   Level     phy_interrupt
 71:          0   IPIC   Level     fsldma-device, fsldma-channel, fsldma-channel, fsldma-channel, fsldma-channel
 74:          0   IPIC   Level     bubbatwo
BAD:         10

and with the command below you can see the amount of interrupts growing:

Code: Select all

watch "grep ath9k /proc/interrupts"

But until now I haven't found a solution for my wifi problems on B2

[Cheeseboy]

Ah, I have the non-wifi model of the B2....

[RandomUsername]

You could try the new beta release, see if it's fixed - http://forum.excito.net/viewtopic.php?f ... 260#p16259

[Krister]

Thanks,

I found that it is ath9k that generates interrupts and slows down my wifi network.

//Krister

[johannes]

The ath9k is the wifi chipset, and the interrupts are probably correct responses to network events.

[Krister]

Hi Johannes,

I've shut down all my wifi clients but ksoftirqd still takes about 25% CPU.

//Krister

[Nöbbe]

I have a similar problem, ksoftirqd uses 40-50% of my B2 CPU. When using the watch command on the interrupts file I see that the ath9k get about 25 000 interrupts every second.

Does this sound normal?

Edit: Added logs of the ksoftirqd cpu usage (from top) and ath9k interrupts from /proc/interrupts taken about every second. There is a time stamp as well in the log.