----------------------------------------------------------------------------
-SimGrid (3.27.1) NOT RELEASED YET (v3.28 expected June 21. 2021, 03:32 UTC)
+SimGrid (3.29.1) NOT RELEASED YET (v3.30 expected December 21. 2021, 15:59 UTC)
+
+Main user-visible changes:
+ - The SimDag API for the simulation of the scheduling of Directed Acyclic
+ Graphs has been dropped. It was marked as deprecated for a couple of years.
+ We finally complete the implementation of what has been called SimDag++
+ internally, i.e., porting the different features of SimDag on top of S4U.
+ The new way to simulate the execution of dependent activities directly by
+ maestro (without any other actor) is details in the examples/cpp/dag-* series
+ of examples.
+ - The removal of SimDag led us to also remove the export to Jedule files that
+ was tightly coupled to SimDag. The instrumentation of DAG simulation is still
+ possible through the regular instrumentation API based on the Paje format.
+ - We also dropped the old and clumsy Lua bindings to create platforms in a
+ programmatic way. It can be done in C++ in a much cleaner way now, which
+ motivates this suppression.
+
+S4U:
+ - Introduce on_X_cb() functions for all signals, to attach a new
+ callback to the signal X. The signal variables are now hidden and
+ only these functions should be used.
+ Rationale: this enables the usual deprecation schema where functions
+ remain for 4 releases if we need to modify the signals, while the
+ current code with the signal variables directly visible prevents any
+ smooth transition.
+ - New function: Engine::run_until(date), to split the simulation.
+ - New signal: Activity::on_veto, to detect when an activity fails to start.
+ - New function: Engine::track_vetoed_activities() to interrupt run()
+ when an activity fails to start, and to keep track of such activities.
+ Please see the corresponding example for more info.
+
+SMPI:
+ - Dynamic costs for MPI operations: New API to allow users to dynamically
+ change injected costs for MPI_Recv, MPI_Send and MPI_Isend operations.
+ Alternative for smpi/or, smpi/os and smpi/ois configuration options.
+
+Documentation:
+ - New section: "SimGrid MPI calibration of a Grid5000 cluster"
+ presenting how to properly calibrate MPI communications in SimGrid.
+ - Complete and reword the platform section, which is now completed.
+
+Python:
+ - Thread contexts are used by default with Python bindings. Other kinds of
+ contexts revealed unstable, specially starting with pybind11 v2.8.0.
+
+Fixed bugs (FG#.. -> FramaGit bugs; FG!.. -> FG merge requests)
+ (FG: issues on Framagit; GF: issues on GForge; GH: issues on GitHub)
+ - FG#95: Wrong computation time for multicore execution after pstate change
+ - FG#97: Wrong computation time for ptask+multicore+pstates
+ - FG#99: Weird segfault when not sealing an host
+
+----------------------------------------------------------------------------
+
+SimGrid (3.29) October 7. 2021
+
+The "Ask a stupid question" release.
+
+We wish that every user ask one question about SimGrid to celebrate.
+On Mattermost, Stack Overflow or using the issues tracker.
+
+
+New modeling features:
+ - Non-linear resource sharing, modeling resources whose performance heavily degrades with contention:
+ - The total capacity may be updated dynamically through a callback
+ and depends mainly on the number of concurrent flows.
+ - Examples (both cpp and python): io-degradation, network-nonlinear, exec-cpu-nonlinear
+
+ - Dynamic factors: model variability in the speed of activities
+ - Each action can now have a factor that affects its progression.
+ This multiplicative factor is applied when updating the amount of work
+ remaining, thereby an activity with factor=0.5 only uses half of the
+ instantaneous power/bandwidth it is allocated and will appear twice
+ slower than what it actually consumes.
+ - This can be used to model a overhead (e.g., there is a 20 bytes
+ header in a 480 bytes TCP packet so the factor 0.9583) but the novelty
+ is this factor can now easily be adjusted depending on activity's and
+ resources characteristics.
+ - This existed for network (e.g., the effective bandwidth depends
+ on the message in SMPI piecewise-linear network model) but it is now
+ more general (the factor may depend on the source and destination and
+ thus account to different behaviors for intra-node communications and
+ extra-node communications) and is available for CPUs (e.g., if you
+ want to model an affinity as in the "Unrelated Machines" problem in
+ scheduling) and disks (e.g., if you want to model a stochastic
+ capacity) too.
+ - For that, resources can be provided with a callback that computes
+ the activity factor when creating the action.
+ - Example: examples/cpp/exec-cpu-factors
+ - The same mechanism is also available for the latency, which
+ allows to easily introduce complex variability patterns.
+
+Python:
+ - Added support to programmatic platform creation in Python.
+ Example: examples/python/clusters-multicpu
+
+S4U:
+ - Disk and Host now have a set_sharing_policy() too, for non-linear sharing.
+ This can only be set through the API, not through XML files.
+
+SMPI:
+ - TI Tracing/Replay:
+ - Multiple fixes to ensure reproducibility of tracing
+ - scan/excan can now be replayed
+ - wait action now uses ranks and not pid, as the other ones.
+ - smpi/init and smpi/finalization-barrier are now valid for replays.
+ - exit() is now intercepted by SMPI to avoid premature shutdown of
+ simulation. First non 0 return codes is returned as simulation return
+ code.
+
+Documentation:
+ * New section "Release Notes" documenting recent and current developments.
+ * New section "Modeling I/O: the realistic way" presenting how to properly model disks in SimGrid.
+ * Improvements in API Reference for C++ and Python interfaces.
+
+ns-3 model:
+ - Make wifi creation compatible with ns-3 version 3.34 too.
+
+Fixed bugs (FG#.. -> FramaGit bugs; FG!.. -> FG merge requests)
+ (FG: issues on Framagit; GF: issues on GForge; GH: issues on GitHub)
+ - FG#78: Multiple fixes for SMPI replay:
+ - TI tracing of allotallv/w was outputting wrong values
+ - MPI_LOGICAL in fortran is actually 32 bits wide, and not 8.
+ - FG#77: Search feature of doc is broken (update sphinx theme version)
+----------------------------------------------------------------------------
+
+SimGrid (3.28) July 14. 2021
+
+The Victoriadagarna Release.
New features:
+ - C++ platform interface: Users can now describe their platform directly in C++.
+ This provides greatly flexibility and performance improvement for complex
+ platforms. Main features:
+ - Fat-Tree/DragonFly/Torus composing: allows you to create clusters of
+ "zones", instead of single hosts. This feature enables the description
+ of clusters with complex hosts, composed of several CPUs, GPUs, etc.
+ - StarZone: new zone with a Star-like topology. The routes are defined
+ as a set of links used to communicate from node to everybody (node<->ALL).
+ - Split-Duplex links: auxiliary method to create split-duplex links in
+ the platform, easing its utilisation. It automatically creates both UP
+ and DOWN links (similarly as done in XML).
+ - Please refer to the documentation and the examples included:
+ e.g. examples/cpp/clusters-multicpu/ and examples/platforms/*.cpp.
- New plugin: Producer-Consumer with monitor. Just requires to include the
include/simgrid/plugins/ProducerConsumer.hpp header to be used. See the
associated example (examples/cpp/plugin-prodcons).
S4U:
+ - New: s4u::Comm::wait_all_for() (like s4u::Comm::wait_all, but with a timeout),
+ s4u::Io::wait_any(), s4u::Io::wait_any_for().
+ - Methods test_all/test_any/wait_all/wait_any in s4u now take their vector
+ parameter by reference, instead of a pointer.
- Fixed a bug where Activity::wait_for() killed the activity on timeout.
Explicitly cancel the activity to get back to previous behavior.
+ - New: Link::set_concurrency_limit() to limit the amount of concurrent flows.
SMPI:
- The default SMPI compiler flags are no more taken from the environment.
They can be explicitly set through cmake parameters SMPI_C_FLAGS,
SMPI_CXX_FLAGS, or SMPI_Fortran_FLAGS.
- - New option: --cfg=smpi/finalization-barrier, which can be used to add
- a barrier inside MPI_Finalize. This can help for some codes which cleanup
- data attached to a process, but still used in other SMPI processes.
-LUA:
- - Lua platform files are deprecated. Their support will be dropped after v3.31.
+ - New options:
+ --cfg=smpi/finalization-barrier: which can be used to add
+ a barrier inside MPI_Finalize. This can help for some codes which cleanup
+ data attached to a process, but still used in other SMPI processes.
+ --cfg=smpi/errors-are-fatal: True by default, behaves like if MPI_ERRORS_RETURN
+ is active when set to false, to keep going after a small error
+ --cfg=smpi/pedantic: True by default. Do not report some harmless MPI errors
+ which may or may not be problematic in the end.
+ - Sampling:
+ - fix behaviour, as maximum iteration count could be ignored
+ - add SMPI_SAMPLE_LOCAL_TAG and SMPI_SAMPLE_GLOBAL_TAG macros, to allow user to
+ use sampling when the same kernel is called with a different set of parameters
+ which have an impact on the timing.
+ - realloc is now intercepted, to be coherent, as malloc/calloc/free were already.
+ It should now work with smpi/auto-shared-malloc-thresh.
+ - Improve error handling and reporting in multiple places
+ - Improve correctness checks on the MPI code.(MPI_Op and MPI_Datatype
+ validity checks, truncated messages are now an error, return errors
+ when explicitely deleted handles are reused, ...)
+ - RMA: multiple fixes and stability improvements.
+ - analysis (-analyze flag in smpirun):
+ - SMPI can now report buffer leaks as well as MPI handles leaks,
+ if code was compiled without SMPI_NO_OVERRIDE_MALLOC.
+ - if -trace-call-location is used when compiling, SMPI can report
+ origin of leaked handles/buffers
+ - group leaks by type/origin in output message if possible
+ - New implemented MPI calls: MPI_Comm_test_inter
-Simix:
- - Legacy functions deprecated in this release: SIMIX_get_clock(), SIMIX_run().
+Models:
+ - Changed internal implementation of bandwidth factors in network models.
+ Models affected: CM02, LV08 (default), SMPI, IB.
+ Configuration affected: "network/bandwidth-factors" and "smpi/bw-factors".
+ Bandwidth factors are applied to communications to describe that users
+ cannot use 100% of the available bandwidth. For example, the default network model,
+ LV08, applies a factor of 0.97 to the bandwidth. In older versions, this
+ behavior was implemented by limiting the bandwidth available in the LMM
+ system for this flow. This may give the false impression that there is
+ bandwidth available for other flows due to its underutilization, especially
+ for the dynamic bandwidth factors used in SMPI models.
+ To avoid this, we have modified the implementation so that each flow uses the
+ maximum physical bandwidth according to the LMM system.
+ However, the actual throughput of the flow seen by the user is defined by
+ the physical bandwidth multiplied by the bandwidth factor.
+ This change impacts on the simulation results for all network models on
+ which we have bandwidth factors configured.
+ *****************************************
+ *DO NOT MIX 3.28 RESULTS WITH OLDER ONES*
+ *****************************************
+ This change may impact on the timing of your simulation results.
+ Take care when comparing simulations from different SimGrid's
+ versions. Sorry for the inconvenience.
+ - Dynamic network factors: users can configure a callback to define
+ the network factors dynamically. This API is available at
+ simgrid::kernel::resource::NetworkModelIntf.
+ - Users have access to complete information about the current communication
+ to decide which factor to apply. This includes: message size, source and
+ destination hosts, links and zones traversed.
+ - Dynamic factors for both latency and bandwidth.
+ - For more details, see the example in (examples/cpp/network-factors).
+ - Plugin host_energy: the "watt_off" and "watt_per_state" host properties,
+ deprecated since version 3.24, are no longer supported. Instead, use
+ "wattage_off" and "wattage_per_state".
XBT:
- xbt_assert is not disabled anymore, even when built with enable_debug=off.
Documentation:
- New tutorial: Model-checking and formal assessment
+ - New sections: "Demystifying the routing" and "C++ platforms"
+ - Update and improve the part on visualization in MPI and Algo tutorials.
+ - Improve the section on routing: how to define it, how it's used internally
+ - Fix many issues, broken links and missing references in doxygen and Sphinx
+
+LUA:
+ - Lua platform files are deprecated. Their support will be dropped after v3.31.
+
+Simix:
+ - Legacy functions deprecated in this release: SIMIX_get_clock(), SIMIX_run().
Fixed bugs (FG#.. -> FramaGit bugs; FG!.. -> FG merge requests)
(FG: issues on Framagit; GF: issues on GForge; GH: issues on GitHub)
