[RF] Show INFO messages on the FastEvaluations topic by default

roofit/roofitcore/src/RooAbsReal.cxx

@@ -98,6 +98,8 @@
 #include <iomanip>
 #include <iostream>
 #include <limits>
+#include <mutex>
+#include <set>
 #include <sstream>
 #include <sys/types.h>
 
@@ -4186,12 +4188,18 @@ void RooAbsReal::doEval(RooFit::EvalContext & ctx) const
     std::vector<ServerData>& _servers;
   } restoreState{ourServers};
 
-
   // Advising to implement the batch interface makes only sense if the batch was not a scalar.
-  // Otherwise, there would be no speedup benefit.
+  // Otherwise, there would be no speedup benefit. Warn only once per class, because doEval() is
+  // called for every evaluation of the computation graph, e.g. in every minimizer iteration.
   if(output.size() > 1 && RooMsgService::instance().isActive(this, RooFit::FastEvaluations, RooFit::INFO)) {
-    coutI(FastEvaluations) << "The class " << ClassName() << " does not implement the faster batch evaluation interface."
-        << " Consider requesting or implementing it to benefit from a speed up." << std::endl;
+     static std::set<std::string> warnedClasses;
+     static std::mutex warnedClassesMutex;
+     std::lock_guard<std::mutex> guard{warnedClassesMutex};
+     if (warnedClasses.insert(ClassName()).second) {
+        coutI(FastEvaluations) << "The class " << ClassName()
+                               << " does not implement the faster batch evaluation interface."
+                               << " Consider requesting or implementing it to benefit from a speed up." << std::endl;
+     }
   }
 
 

roofit/roofitcore/src/RooFit/Evaluator.cxx

@@ -44,7 +44,9 @@ RooAbsPdf::fitTo() is called and gets destroyed when the fitting ends.
 
 #include <chrono>
 #include <iomanip>
+#include <mutex>
 #include <numeric>
+#include <set>
 #include <thread>
 #include <unordered_set>
 
@@ -91,6 +93,28 @@ void logArchitectureInfo(bool useGPU)
    }
 }
 
+/// Advise the user to implement CUDA support for a class that had to be
+/// evaluated on the CPU even though the CUDA backend was requested. Just like
+/// for the analogous message about the missing batch evaluation interface in
+/// RooAbsReal::doEval(), the message is only printed once per class, because
+/// the computation graph is evaluated many times, e.g. in every minimizer
+/// iteration.
+void logMissingCudaSupport(RooAbsArg const &arg)
+{
+   if (!RooMsgService::instance().isActive(&arg, RooFit::FastEvaluations, RooFit::INFO)) {
+      return;
+   }
+   static std::set<std::string> warnedClasses;
+   static std::mutex warnedClassesMutex;
+   std::lock_guard<std::mutex> guard{warnedClassesMutex};
+   if (warnedClasses.insert(arg.ClassName()).second) {
+      oocoutI(&arg, FastEvaluations) << "The class " << arg.ClassName()
+                                     << " could not be evaluated on the GPU because it doesn't support it."
+                                     << " Consider requesting or implementing it to benefit from a speed up."
+                                     << std::endl;
+   }
+}
+
 } // namespace
 
 /// A struct used by the Evaluator to store information on the RooAbsArgs in
@@ -357,12 +381,10 @@ void Evaluator::computeCPUNode(const RooAbsArg *node, NodeInfo &info)
          _evalContextCUDA.set(node, {buffer, nOut});
       }
    } else {
+      // Advising to implement the CUDA evaluation makes only sense if the batch was not a scalar.
+      // Otherwise, there would be no speedup benefit.
       if (!info.hasLogged && _useGPU) {
-         RooAbsArg const &arg = *info.absArg;
-         oocoutI(&arg, FastEvaluations) << "The argument " << arg.ClassName() << "::" << arg.GetName()
-                                        << " could not be evaluated on the GPU because the class doesn't support it. "
-                                           "Consider requesting or implementing it to benefit from a speed up."
-                                        << std::endl;
+         logMissingCudaSupport(*info.absArg);
          info.hasLogged = true;
       }
       if (!info.buffer) {

roofit/roofitcore/src/RooMsgService.cxx

@@ -27,8 +27,9 @@ RooMsgService allows to filter and redirect messages into streams
 according to message level, topic, (base) class of originating object, name of originating
 object and based on attribute labels attached to individual objects.
 The current default configuration creates streams for all messages at WARNING level
-or higher (e.g. ERROR and FATAL) and for all INFO message on topics Generation,Plotting,
-Integration and Minimization and redirects them to stdout. Users can create additional streams
+or higher (e.g. ERROR and FATAL) and for INFO messages on most topics (among others
+Generation, Plotting, Minimization, and FastEvaluations) and redirects them to stdout.
+Users can create additional streams
 for logging of e.g. DEBUG messages on particular topics or objects and/or redirect streams to
 C++ streams or files.
 
@@ -47,7 +48,6 @@ RooHelpers::HijackMessageStream allows to fully capture a message stream in a st
 RooFit messages can be evaluated or suppressed.
 **/
 
-
 #include "RooMsgService.h"
 
 #include <sys/types.h>
@@ -123,7 +123,9 @@ void RooMsgService::reset() {
   // Old-style streams
   _streams.clear();
   addStream(RooFit::PROGRESS, Topic(RooFit::HistFactory - 1));//All before HistFactory
-  addStream(RooFit::INFO,Topic(RooFit::Eval|RooFit::Plotting|RooFit::Fitting|RooFit::Minimization|RooFit::Caching|RooFit::ObjectHandling|RooFit::NumericIntegration|RooFit::InputArguments|RooFit::DataHandling)) ;
+  addStream(RooFit::INFO, Topic(RooFit::Eval | RooFit::Plotting | RooFit::Fitting | RooFit::Minimization |
+                                RooFit::Caching | RooFit::ObjectHandling | RooFit::NumericIntegration |
+                                RooFit::InputArguments | RooFit::DataHandling | RooFit::FastEvaluations));
   addStream(RooFit::INFO, Topic(RooFit::HistFactory));
 }