From ce3e6a7cb21d1aa455513970846e1f70c01472a4 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Fri, 14 Aug 2020 14:56:18 +0300
Subject: bench: Allow skip benchmark

Co-authored-by: Martin Ankerl <Martin.Ankerl@gmail.com>
---
 src/bench/bench.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'src/bench')

diff --git a/src/bench/bench.cpp b/src/bench/bench.cpp
index 01466d0b6f..012057e792 100644
--- a/src/bench/bench.cpp
+++ b/src/bench/bench.cpp
@@ -70,7 +70,10 @@ void benchmark::BenchRunner::RunAll(const Args& args)
             }
             std::cout << bench.complexityBigO() << std::endl;
         }
-        benchmarkResults.push_back(bench.results().back());
+
+        if (!bench.results().empty()) {
+            benchmarkResults.push_back(bench.results().back());
+        }
     }
 
     GenerateTemplateResults(benchmarkResults, args.output_csv, "# Benchmark, evals, iterations, total, min, max, median\n"
-- 
cgit v1.2.3


From 3edc4e34fe2f92e7066c1455f5e42af2fdb43b99 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Fri, 14 Aug 2020 14:58:27 +0300
Subject: bench: Prevent thread oversubscription

This change decreases the variance of benchmark results.
---
 src/bench/checkqueue.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'src/bench')

diff --git a/src/bench/checkqueue.cpp b/src/bench/checkqueue.cpp
index 19d7bc0dbc..ffa772d8c1 100644
--- a/src/bench/checkqueue.cpp
+++ b/src/bench/checkqueue.cpp
@@ -14,8 +14,6 @@
 
 #include <vector>
 
-
-static const int MIN_CORES = 2;
 static const size_t BATCHES = 101;
 static const size_t BATCH_SIZE = 30;
 static const int PREVECTOR_SIZE = 28;
@@ -26,6 +24,9 @@ static const unsigned int QUEUE_BATCH_SIZE = 128;
 // and there is a little bit of work done between calls to Add.
 static void CCheckQueueSpeedPrevectorJob(benchmark::Bench& bench)
 {
+    // We shouldn't ever be running with the checkqueue on a single core machine.
+    if (GetNumCores() <= 1) return;
+
     const ECCVerifyHandle verify_handle;
     ECC_Start();
 
@@ -44,7 +45,9 @@ static void CCheckQueueSpeedPrevectorJob(benchmark::Bench& bench)
     };
     CCheckQueue<PrevectorJob> queue {QUEUE_BATCH_SIZE};
     boost::thread_group tg;
-    for (auto x = 0; x < std::max(MIN_CORES, GetNumCores()); ++x) {
+    // The main thread should be counted to prevent thread oversubscription, and
+    // to decrease the variance of benchmark results.
+    for (auto x = 0; x < GetNumCores() - 1; ++x) {
        tg.create_thread([&]{queue.Thread();});
     }
 
-- 
cgit v1.2.3