[Openmp-dev] Runtime error when executing multiple target regions within a target data region

[Joachim Protze via Openmp-dev]

Hi all,

we experience strange errors when we try to launch multiple target 
regions within a data region, see attached code. The result when using 
unstructured data mapping is similar. We are using clang built from 
trunk this week.

When we map the data for each iteration (as in line 23), the whole code 
runs through. When we use a larger value for TEAMS, the execution falls 
back to the host in an earlier iteration (for 1024 in the second 
iteration instead of 7th as shown below).

So, there seems to be an issue with the allocation of teams, when the 
data region stays open. Any ideas, how this can be fixed?

Best,
Joachim


Output when running the attached code (num_teams, thread_limit, 
is_initial_device):

256, 992, 0
0
256, 992, 0
1
256, 992, 0
2
256, 992, 0
3
256, 992, 0
4
256, 992, 0
5
256, 992, 0
OMP: Warning #96: Cannot form a team with 256 threads, using 48 instead.
OMP: Hint Consider unsetting KMP_DEVICE_THREAD_LIMIT (KMP_ALL_THREADS), 
KMP_TEAMS_THREAD_LIMIT, and OMP_THREAD_LIMIT (if any are set).
48, 2147483647, 1
6
48, 2147483647, 1
7
48, 2147483647, 1
8
48, 2147483647, 1
9
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