<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Times New Roman; font-size: 12pt; color: #000000'><blockquote id="DWT2834" style="border-left:2px solid rgb(16, 16, 255);margin-left:5px;padding-left:5px;"><div><br></div><div>Probably I've made a bad example for you</div><div>I attach the same mesh, distributed for 4 processors, it have no adjacent edges and it passes exchange_ghost_cells</div><div>If you partition the mesh by mbpart with the same command for 1-5,8,10,13,15 processors then it works, but for any other number of processors up to 20 it don't</div><div>The problem is that there are certain mesh decompositions on which function hangs. I have another mesh which also hangs</div><div>I attach bug.cpp that create adjacencies but still hangs</div><div>exchange_ghost_cells rely on get_bridge_adjacencies which rely on get_adjacencies and it worked for me even when adjacencies were not created</div><div><br></div><div></div><br><div></div><br></blockquote>OK.<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><div></div></blockquote>it hangs for me for any np>4; if you have only 4 parts, at least one of the processors will not get anything<br>it should not hang, I agree, we should handle it more gracefully.<br><br>Thanks for submitting these errors. I will let you know what I find.<br><br>Iulian<br></div></body></html>