Hi Brian, (I am also cc-ing the MPI-3 tools group) At the last forum you had some concerns about the text passage in the MPI_T proposal regarding signal safety. We have rewritten the text - what do you think about the advice to implementors below? Does this address your concerns? Thanks, Martin Sampling based tools rely on the ability to call the MPI tool information interface, in particular routines to start, stop, read, write and reset performance variables, from any program context, including asynchronous contexts such as signal handlers. MPI implementations should strive, if possible in their particular environment, to enable these usage scenarios for all or a subset of the routines mentioned above. If implementing only a subset, the read, write, and reset routines are typically the most critical for sampling based tools. An MPI implementation should clearly document any restrictions on the program contexts in which the MPI tool information interface can be used. Restrictions might include guaranteeing usage outside of all signals or outside a specific set of signals. Any restrictions could be documented, for example, through the description returned by \mpifunc{MPI\_T\_PVAR\_GET\_INFO}. ________________________________________________________________________ Martin Schulz, [email protected], http://people.llnl.gov/schulzm CASC @ Lawrence Livermore National Laboratory, Livermore, USA