X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/03557c48c5faa4d624b1933365e8317ea44668f9..d458ebe1aba729edab80a8d1f3d469c886345bf2:/ChangeLog diff --git a/ChangeLog b/ChangeLog index 10bc26e32a..ec1a79743c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,53 +1,117 @@ ---------------------------------------------------------------------------- -SimGrid (3.28.1) NOT RELEASED YET (v3.29 expected September 22. 2021, 19:21 UTC) +SimGrid (3.29.1) NOT RELEASED YET (v3.30 expected December 21. 2021, 15:59 UTC) -New features: - - Non-linear resource sharing: allows to dynamically change the resource - capacity. Users can change this capacity by setting a callback which will - be called when SimGrid is sharing the resource between the active - activities. An activity can be a task running, a read/write IO operation or a - communication flow. - - Callback signature: double (double capacity, int n_activities): given the - current resource's capacity and number of activities running on it, - returns the new capacity. - - Note that this callback is in the critical path of the system solve and - should not take long to execute. - - Examples: - - Disk: examples/cpp/io-degradation - - Link: examples/cpp/network-nonlinear - - CPU: examples/cpp/exec-cpu-nonlinear - - Dynamic factors for CPU and disk: similarly to dynamic network factors, - allows the user to set a callback which can affect the progress of activities - (multiplicative factor applied when updating the amount of work remaining). - - Example: examples/cpp/exec-cpu-factors +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. - - Several new methods were added to Python interface. For more details, see - the corresponding documentation. - - New python examples: - - Clusters: examples/python/clusters-multicpu - - Disk: examples/python/io-degradation - - CPU: examples/python/exec-cpu-nonlienar - - Link: examples/python/network-nonlinear + Example: examples/python/clusters-multicpu S4U: - - New: s4u::Disk::set_sharing_policy() and s4u::Host::set_sharing_policy(). - Allows the configuration of non-linear resource sharing for hosts and - disks. + - 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. + - 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. + * 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: