Re: [Openmosix-devel] 2.6.11.12-om low max bandwidth

[thunderlord <thu...@ra...>]

Hi again!

I understand that using a global cluster filesystem would be a great=20
choice, but for my small cluster of 2, maybe 3 nodes I think it is not=20
necessary. I just want to speed up data transfer between stub process on=20
home node and worker process on another node. Currently it looks like=20
some bandwidth limit is set for each migrated process, limiting=20
bandwidth to 800-900 Kbit/s, so the only way to make my 935Mhz Duron to=20
work at ~99% CPU usage is to migrate enough processes, then overall=20
badwidth grows in arithmetic progression, but this is not always acceptab=
le.
*So my question is: does anybody know where in kernel code could be such=20
a function/piece of code that limits data transfer rates between=20
stub(deputy) process (which fetches data from harddisk on home node) and=20
worker process on another node?*
I analized changes that openmosix patch make to vanilla kernel code and=20
found several possible places, but to test them all can take a lot of=20
time, because i am not so good in kernel development, and do not know=20
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 <thu...@ra...> wrote:
> =20
>
>>Hi all!
>>
>>I am using 2.6.11.12-om and noticed that any migrated process doesn=B4t
>>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=B4ve 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.
>>
>>
>>
>>-------------------------------------------------------
>>SF.Net email is sponsored by:
>>Tame your development challenges with Apache's Geronimo App Server.
>>Download it for free - -and be entered to win a 42" plasma tv or your v=
ery
>>own Sony(tm)PSP.  Click here to play: http://sourceforge.net/geronimo.p=
hp
>>_______________________________________________
>>openMosix-devel mailing list
>>ope...@li...
>>https://lists.sourceforge.net/lists/listinfo/openmosix-devel
>>
>>   =20
>>
>
> =20
>