[Problem] High CPU usage during LAN file transfers (7270v3, 05.51)

[SilvioMoioli]

Hi everyone,

I noticed that my 7270v3 (currently with FRITZ! 05:51 OS) uses a lot of CPU (especially in software IRQ) during simple file transfers, even during internal-only file transfers (eg. between laptop and NAS). Typical example:

    # top

    Mem: 50820K used, 8480K free, 0K shrd, 4856K buff, 16060K cached
    CPU:  0.3% usr  1.9% sys  0.0% nic 15.8% idle  0.0% io  5.6% irq 76.2% sirq
    Load average: 1.53 1.20 0.78 2/73 2213
      PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
      232     2 root     SW       0  0.0   0  8.0 [capi_schedw/0]
     2211  2167 root     R     1440  2.4   0  7.0 top
        3     2 root     SW       0  0.0   0  6.8 [ksoftirqd/0]
     1870     2 root     RWN      0  0.0   0  4.9 [kdsld_token]

Even without top, almost 80% of CPU time in sirq seems a little too much to me.

I noticed that QoS filters have a measurable, but not substantial, impact on CPU usage. In your opinion, is this normal? Is it possible to improve the situation with Freetz, which options would you recommend?

Thanks in advance!

 

[devdev]

Yes, this is the normal case. If you use NAS of the Fritzbox the CPU limits the bandwith. In case of a faster Fritzbox e.g. 7390 or 7360 you get more speed (5-10MB/sec) but the cpu-load is also up to 100 percent.

 

[SilvioMoioli]

If you use NAS of the Fritzbox the CPU limits the bandwith.

Actually I am using a separate NAS, not the one in the Fritz!Box, and the same happens with other devices, too (eg. AppleTV).

Sorry for the misunderstading - my post was not very clear!

 

[SaschaBr]

I think, this totaly normal. I've seen this on my former 7390 too (i've sold this device). Now i am using an cheap allnet-gigabit-switch instead the fritz!box as switch, and many network-performance-problems has gone.

 

[RalfFriedl]

Even without top, almost 80% of CPU time in sirq seems a little too much to me.

Where did you get that 80% from?

 

[SilvioMoioli]

Where did you get that 80% from?

From the second line in top's output:

CPU:  0.3% usr  1.9% sys  0.0% nic 15.8% idle  0.0% io  5.6% irq 76.2% sirq

"76.2% sirq" at the end. Am I missing something maybe?

SaschaBr: thank you for the input!

Everyone: I might consider using an external switch as SaschaBr suggested; problem is that wireless transfers will need to go through the Fritz!Box anyway, unfortunately. So any further idea on how to lower that number is anyway greatly appreciated!

 

[SaschaBr]

... problem is that wireless transfers will need to go through the Fritz!Box anyway, ...

All my wireless clients use the Fritz!Box as WLAN-Accespoint, but: my Fritz!Box (6360_cable) has also gigabit-lan.
I think, you might buy a newer box with gigabit-lan and wlan (must not to be a Fritz!Box ).