On Fri, Jul 12, 2013 at 10:24:48AM -0500, Pavan Balaji wrote:
Rob,
Sorry, I'll look into this next week.
no need to apologize. I've been there -- twice.
Amount of time left is proportional to age of baby.
The first solution works for some cases in MPICH, but there are still many bugs. I think your ticket is to fix this part?
The second solution is known not to work.
OK, I don't think there's any way to decouple these two solutions, though. There are lots of places in the datatype/dataloop code where optimizations are applied : "oh these two contig types are next to each other. Let's combine them into a single contig type... with a count that overflows. " ==rob
-- Pavan
On 07/12/2013 06:25 AM, Rob Latham wrote:
I've been trying to tackle tt #1742, #1890, and #1893 as part of some I/O work that uses large datatypes.
Am I stepping on anyone's toes here? Pavan, I know i bugged you about these tickets. Hope I didn't waste my Thursday on this...
Pavan told me there are two problems here, but I think there are really one solution to both:
- large datatype means a datatype that describes more than 2 gigs of data. A million contigs of a million contigs, say
- large count means datatypes that use MPI_Count to say how many elements they have: a contig of 3 billion MPI_BYTES, say
Internally, though, there's no way to decouple those two problems.
The changes are pervasive and make me really nervous.
I've been sometimes pushing changes to the ticket-1742-bigio branch.
Who can review datatype changes once I'm done?:
==rob
-- Rob Latham Mathematics and Computer Science Division Argonne National Lab, IL USA