[openib-general] Re: SDP_IOCB_SIZE_MAX

[Michael S. Tsirkin]

Quoting r. Libor Michalek <limichal at cisco.com>:
> Subject: Re: SDP_IOCB_SIZE_MAX
> 
> On Mon, Aug 01, 2005 at 04:26:16PM +0300, Michael S. Tsirkin wrote:
> > Libor, in sdp_iocb.h we have:
> > 
> > sdp_iocb.h:#define SDP_IOCB_SIZE_MAX (128*1024) /* matches AIO max kvec size. */
> > 
> > What does the comment mean?
> 
>   This is left over from the the old 2.4 AIO code. The AIO layer use to
> break larger AIOs into chunks, and 128K was the default size. It's used
> to set the size of the FMRs, so I would expect IOs larger then this to
> fail because the registration will fail. Since FMRs need to be a fixed
> size, if we wish to continue using them, we'll need to break AIOs over
> a certain size into multiple iocbs and advts...

Yes.

> > I seem to have no trouble passing requests bigger than 128K to SDP:
> 
>   Really? I just tried it and it definetly didn't work...
> 
> -Libor
> 

I mean they get passed to the SDP layer. Of course they cant get sent.

-- 
MST