Re: [Starpu-devel] Unexpected behavior - Not making task ready when they could be

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Hello,

Berenger Bramas, le Fri 13 Feb 2015 11:51:43 +0100, a écrit :
> In the test I am submitting lots of tasks that use two handles in STARPU_RW|
> STARPU_COMMUTE.

COMMUTE does not mean that the tasks can access the data concurrently.
It only means that they can be run in either order, but still in
exclusion: there can be only one writer.  This is because in a
distributed environment it does not make sense to let several tasks
write to the same data. Implementing some STARPU_CONCURRENT_WRITE flag
should be possible, it has been on the TODO list for some time already,
the "only" difficult part is preventing it from letting tasks go over
different memory nodes. In the particular case of a CPU-only task, it
would probably be relatively easy to implement.

Samuel