[openib-general] Re: SDP_IOCB_SIZE_MAX

[Libor Michalek]

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...

> 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