[Barrelfish-users] System V Shared memory

[Zeus Gómez Marmolejo]

Hey Gerd,

Yes, it's perfect. Now there is no error anymore. Thank you very much!!


zeus.


2012/2/16 Gerd Zellweger <zgerd at student.ethz.ch>

>  Hi Andrew and Zeus,
>
> I have written a replacement for the nameserver a couple of days ago.
> However, over time additional functionality has been added to chips to
> write implementations for posixcompat: A capability storage and a
> distributed semaphore API. The error Zeus is seeing right now seems related
> to the capability storage since shmget/shmat is using this piece of code. I
> have discussed this with Adrian a bit today and we're currently not sure if
> these APIs should remain in chips or if I should transfer these over to the
> new service (which would be a hack as the new service builds upon the SKB
> and the SKB does not (yet) support storage for capabilities).
> In addition, because the ECLiPSe CLP engine (used by the SKB) uses some
> inline x86 assembler we still need chips for non-x86 architectures at the
> moment. Since we can't get completely rid of chips yet I made a patch that
> should fix the send handlers.
>
> @Zeus: I could not reproduce your bug on my machine but the error should
> be fairly straight-forward to fix. Feedback is appreciated if this works
> for you.
>
> Gerd
>
>
>
> On 02/16/2012 05:18 PM, Baumann Andrew wrote:
>
>  Hi Zeus,****
>
> ** **
>
> This is an implementation bug in chips: it doesn’t handle the TX_BUSY
> error (and gets away with it, because most clients use chips only as an RPC
> service). It would be possible to fix that by queuing up the sends, as we
> do in other services, but I’m not in a hurry to do that as I believe there
> was a masters project at ETH to replace chips with something better…
> perhaps someone can fill us in on the status of this, and if there are any
> merge plans?****
>
> ** **
>
> Andrew****
>
> ** **
>
> *From:* Zeus Gómez Marmolejo [mailto:zeus.gomez at bsc.es <zeus.gomez at bsc.es>]
>
> *Sent:* Thursday, 16 February, 2012 4:50
> *To:* barrelfish-users at lists.inf.ethz.ch
> *Subject:* [Barrelfish-users] System V Shared memory****
>
> ** **
>
> Hi all,****
>
> ** **
>
> I have been trying the shmget() shmat() functions present in the
> posixcompat library, which are not used by any program in Barrelfish. I've
> made two very simple programs shm_client and shm_server which export a
> shared memory and waits for the other to write on it. I attach the two
> programs.****
>
> ** **
>
> The system seems to work even on different cores, but in this case I
> always get an error on chips forcing it to abort:****
>
> ** **
>
> ERROR: chips.0 in get_service_reference_handler()
> /home/zeus/bsc/bf/usr/chips/framework.c:167****
>
> get_service_reference_response failed****
>
> Failure: (       flounder) Cannot queue message for transmit: queue is
> full [FLOUNDER_ERR_TX_BUSY]****
>
> ** **
>
> (I removed the original assert to see the error).****
>
> ** **
>
> I guess the waitset has to be serviced to process the ACKs and empty the
> queue. But, this function is being called on the event handler.****
>
> ** **
>
> Do you think is there an easy fix to this problem?****
>
> ** **
>
> Thanks,****
>
> ** **
>
> --
> Zeus Gómez Marmolejo
> Barcelona Supercomputing Center
> PhD student
> http://www.bsc.es
>
> ****
>
>
> _______________________________________________
> Barrelfish-users mailing listBarrelfish-users at lists.inf.ethz.chhttps://lists.inf.ethz.ch/mailman/listinfo/barrelfish-users
>
>
>


-- 
Zeus Gómez Marmolejo
Barcelona Supercomputing Center
PhD student
http://www.bsc.es
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