[Lustre-discuss] socknal_sd00 100% lower?

[Brock Palen]

On Mar 7, 2008, at 8:51 AM, Maxim V. Patlasov wrote:

> Brock,
>
>> If our IO servers are seeing extended periods of socknal_sd00 at  
>> 100%  cpu,  Would this cause a bottle neck?
> Yes, I think so.
>
>> If so its a single homed  hosts, would adding another interface to  
>> the host help?
>>
> Probably, no. It could only help in the case you have several CPUs  
> but something prevents ksocklnd to spread the load over them.

The servers are dual cpu systems.  But I only see a single socknal_sd  
thread.

>
>> Is there threading anyplace?
> Yes, ksocklnd spawns separate socknal_sd thread for each CPU/core  
> that you have. There are two algorithms of spreading the load  -  
> you can play with enable_irq_affinity modparam flag.

I see some things in logs about setting cpu affinity,  Ill check out  
the manual some more,

>
>> Or is faster cpu the only way out?
>>
> I believe you either need faster CPU or faster system bus. If slow  
> system bus isn't your case, increasing number of CPUs also will do.

Ok

>
> Sincerely,
> Maxim
>
>