-- Improve the Python usability (stability and documentation).
- - A nasty synchronization bug was ironed out, see also below.
- - Python's doc was organized as a separate tree, now integrated with C++.
- - C bindings of S4U were not part of the doc.
- - The C++ doc was also improved as methods are now split by theme.
-- Further deprecate MSG: you now have to pass -Denable_msg=ON to cmake.
- - This is mandatory to use the Java bindings.
- - OFF by default; The plan is to completely remove MSG by 2020Q4 or 2021Q1.
-- SimDAG++: Automatic dependencies on S4U activities (experimental)
- - Some features are already implemented but not all of them
- - Cannot block an activity until it's scheduled on a resource
- - No heterogeneous wait_any() that would mix Exec/Comm/Io activities.
- - See examples/s4u/{io,exec,comm}-dependent for what's already there.
+ - SimGrid now requires a compiler with C++14 support.
+ Sibling projects should upgrade their FindSimgrid.cmake
+ - Surf precision default value is now 1e-9, instead of 1e-5. This was changed as
+ several users had difficulties to understand issues when using high bandwidth or
+ small latency events. The new value was already the default for SMPI and
+ should not cause too much performance hit. It can change some simulation
+ timings if simulation was skipping a lot of small events (which was actually
+ an issue per see). The old value can be restored with --cfg=surf/precision:1e-5.
+ - On some network models (L07, CM02, LV08), an implicit loopback link is created
+ for local communication. Default bandwidth was 500MBps and latency was 15µs,
+ which was rather bad. Default values have been changed to 10GBps and 0 latency.
+ Options network/loopback-lat and network/loopback-bw have been added to adapt
+ these values if needed. Network and routing models already providing separate
+ loopbacks (clusters and such) are not impacted by this change.
+ - SMPI now adds 16 bytes of header to each message sent, in order to simulate
+ metadata that are added to each MPI message by MPI libraries (tag,
+ src/dest, and communicator information). This may change simulation times
+ for very small message sizes, but should be more realistic.
+
+New features:
+ - New routing 'WiFi' that makes it easier to specify a wifi network zone.
+ - New plugins: wifi_energy and link_load. See the associated examples.
+ - New examples: wifi networks, and communication suspend.
+
+General:
+ - LTO is now enabled for Intel/clang compilers.
+ - LTO behavior on GCC can be parameterized using LTO_EXTRA_FLAG in cmake.
+ Setting it to "auto" will use all available cores, while setting it to n will
+ use n cores to speedup link step (usage: cmake -DLTO_EXTRA_FLAG=4).
+ - Remove obsolete runtime option 'contexts/parallel-threshold'.
+ - Runtime option 'tracing/msg/process' renamed to 'tracing/actor'. The old name
+ has been kept for compatibility.
+ - Finally remove obsolete snake_case() aliases for runtime options.
+ - Further improve the documentation.
+
+S4U:
+ - the on_exit() of each actor is also executed when the simulation deadlocks.
+ - New functions: s4u::Activity:: suspend(), resume() and is_suspended()
+ An example is provided for s4u::Comm but it should work with Exec and Io.
+
+SMPI:
+ - Update proxy apps coverage of new ECP apps: 60+ apps now tested nightly on
+ https://framagit.org/simgrid/SMPI-proxy-apps
+ - MPI/IO: supports names starting with "./"
+ - Fortran: many MPI/IO bindings, support for MPI_UB/LB, C MPI_INT/FLOAT/DOUBLE
+ datatypes.
+ - smpicc/cxx/ff/f90 now will actually perform definition checks at link time. When
+ building shared libraries, this may cause issues, so environment variable
+ SMPI_NO_UNDEFINED_CHECK can be added to disable this.
+ - most temporary files should now be created in /tmp dir (or equivalent).
+ If this one does not allow execution of code (noexec flag), this may cause issues.
+ Please use another tmp directory (using TMPDIR or equivalent system variable)
+ in this case.
+
+Model-Checker:
+ - A large refactoring is ongoing, but this should be transparent for users so far.