Re: 2.6.11.12-om low max bandwidth

Hi again!

I understand that using a global cluster filesystem would be a great 
choice, but for my small cluster of 2, maybe 3 nodes I think it is not 
necessary. I just want to speed up data transfer between stub process on 
home node and worker process on another node. Currently it looks like 
some bandwidth limit is set for each migrated process, limiting 
bandwidth to 800-900 Kbit/s, so the only way to make my 935Mhz Duron to 
work at ~99% CPU usage is to migrate enough processes, then overall 
badwidth grows in arithmetic progression, but this is not always acceptable.
*So my question is: does anybody know where in kernel code could be such 
a function/piece of code that limits data transfer rates between 
stub(deputy) process (which fetches data from harddisk on home node) and 
worker process on another node?*
I analized changes that openmosix patch make to vanilla kernel code and 
found several possible places, but to test them all can take a lot of 
time, because i am not so good in kernel development, and do not know 
openmosix kernel code good enough.

Thanks in advance.

Evan Hisey wrote:

>Thunderlord-
>  That would seem to be right. oM is ideal crunching numbers not
>accessing harddrives across a network. I think you may also be
>confussed about how oM works. It moves the whole proccess to teh new
>host, leaving only a stub behind on the lauching node. It does not
>'spawn' new versions of the application to move to new nodes. Fora
>while oM used DFSA and oMFS to solve the data transfer issue but it
>became to ugly to maintain. Current recommendation is to look at
>setting up a global cluster filesystem(not NFS).
>
>Evan
>
>On 9/15/05, thunderlord <[email protected]> wrote:
>  
>
>>Hi all!
>>
>>I am using 2.6.11.12-om and noticed that any migrated process doesn´t
>>use all bandwidth avaliable for interprocess communication between
>>deputy and master processes - maximum is 800-900 Kbit/s for each
>>migrated process. So, any program that uses significant amounts of data
>>to operate consumes only 3-30% of CPU time (tested on
>>lame,ffmpeg,bzip2). I use same kernel on both nodes. I´ve tried to
>>recompile kernel with different configurations, but no results. Is this
>>bug known? How can i fix it?
>>
>>My configuration: 2 nodes:
>>1 - master - 1800 Duron, SDRAM 512Mb
>>2 - slave - 935 Duron, SDRAM 256Mb
>>Network - Ethernet 100BaseT.
>>
>>
>>
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>>    
>>
>
>  
>



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