Merge pull request #26852 from vespa-engine/balder/cap-initialize-thread-pool-at-num-cores

Cap the initialize thread pool at number of cores

4 files changed, 26 insertions, 8 deletions

diff --git a/searchcore/src/tests/proton/server/initialize_threads_calculator/initialize_threads_calculator_test.cpp b/searchcore/src/tests/proton/server/initialize_threads_calculator/initialize_threads_calculator_test.cpp
index 7aad69076ca..fc899f3a8c7 100644
--- a/searchcore/src/tests/proton/server/initialize_threads_calculator/initialize_threads_calculator_test.cpp
+++ b/searchcore/src/tests/proton/server/initialize_threads_calculator/initialize_threads_calculator_test.cpp
@@ -16,7 +16,8 @@ public:
 void
 expect_successful_init(uint32_t exp_threads)
 {
-    InitializeThreadsCalculator i("tmp", 9);
+    constexpr uint32_t cfg_threads = 9;
+    InitializeThreadsCalculator i(HwInfo::Cpu(cfg_threads), "tmp", cfg_threads);
     EXPECT_EQ(exp_threads, i.num_threads());
     EXPECT_TRUE(i.threads().get() != nullptr);
     EXPECT_EQ(exp_threads, dynamic_cast<const ThreadStackExecutor&>(*i.threads()).getNumThreads());
@@ -27,7 +28,7 @@ expect_successful_init(uint32_t exp_threads)
 void
 expect_aborted_init(uint32_t exp_threads, uint32_t cfg_threads = 9)
 {
-    InitializeThreadsCalculator i("tmp", cfg_threads);
+    InitializeThreadsCalculator i(HwInfo::Cpu(cfg_threads), "tmp", cfg_threads);
     EXPECT_EQ(exp_threads, i.num_threads());
     EXPECT_TRUE(i.threads().get() != nullptr);
     EXPECT_EQ(exp_threads, dynamic_cast<const ThreadStackExecutor&>(*i.threads()).getNumThreads());
@@ -53,7 +54,7 @@ TEST_F(InitializeThreadsCalculatorTest, initialize_threads_cut_in_half_when_init
 TEST_F(InitializeThreadsCalculatorTest, zero_initialize_threads_is_special)
 {
     {
-        InitializeThreadsCalculator i("tmp", 0);
+        InitializeThreadsCalculator i(HwInfo::Cpu(10), "tmp", 0);
         EXPECT_EQ(0, i.num_threads());
         EXPECT_TRUE(i.threads().get() == nullptr);
     }
@@ -61,4 +62,20 @@ TEST_F(InitializeThreadsCalculatorTest, zero_initialize_threads_is_special)
     expect_aborted_init(1, 0);
 }
 
+void
+expect_lower(uint32_t cores, uint32_t configured) {
+    InitializeThreadsCalculator i(HwInfo::Cpu(cores), "tmp", configured);
+    EXPECT_EQ(std::min(cores, configured), i.num_threads());
+    i.init_done();
+}
+
+TEST_F(InitializeThreadsCalculatorTest, lower_of_wanted_and_cores)
+{
+    expect_lower(1, 7);
+    expect_lower(6, 7);
+    expect_lower(7, 7);
+    expect_lower(7, 6);
+    expect_lower(7, 1);
+}
+
 GTEST_MAIN_RUN_ALL_TESTS()
diff --git a/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.cpp b/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.cpp
index 17ddabebb65..bb1325acf04 100644
--- a/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.cpp
@@ -39,10 +39,11 @@ const vespalib::string file_name = "initialize-threads.txt";
 
 namespace proton {
 
-InitializeThreadsCalculator::InitializeThreadsCalculator(const vespalib::string& base_dir,
+InitializeThreadsCalculator::InitializeThreadsCalculator(const HwInfo::Cpu & cpu_info,
+                                                         const vespalib::string& base_dir,
                                                          uint32_t configured_num_threads)
     : _path(base_dir + "/" + file_name),
-      _num_threads(configured_num_threads),
+      _num_threads(std::min(cpu_info.cores(), configured_num_threads)),
       _threads()
 {
     if (std::filesystem::exists(_path)) {
diff --git a/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.h b/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.h
index 509db24ebf3..e7e1b22f181 100644
--- a/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.h
+++ b/searchcore/src/vespa/searchcore/proton/server/initialize_threads_calculator.h
@@ -2,6 +2,7 @@
 
 #pragma once
 
+#include <vespa/searchcore/proton/common/hw_info.h>
 #include <vespa/vespalib/stllike/string.h>
 #include <vespa/vespalib/util/threadexecutor.h>
 #include <filesystem>
@@ -25,8 +26,7 @@ namespace proton {
      InitializeThreads _threads;
 
  public:
-     InitializeThreadsCalculator(const vespalib::string& base_dir,
-                                 uint32_t configured_num_threads);
+     InitializeThreadsCalculator(const HwInfo::Cpu & cpu_info, const vespalib::string& base_dir, uint32_t configured_num_threads);
      ~InitializeThreadsCalculator();
      uint32_t num_threads() const { return _num_threads; }
      InitializeThreads threads() const { return _threads; }
diff --git a/searchcore/src/vespa/searchcore/proton/server/proton.cpp b/searchcore/src/vespa/searchcore/proton/server/proton.cpp
index 8ec904760cf..7f3dc02aba8 100644
--- a/searchcore/src/vespa/searchcore/proton/server/proton.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/proton.cpp
@@ -352,7 +352,7 @@ Proton::init(const BootstrapConfig::SP & configSnapshot)
     vespalib::string fileConfigId;
     _compile_cache_executor_binding = vespalib::eval::CompileCache::bind(_shared_service->shared_raw());
 
-    InitializeThreadsCalculator calc(protonConfig.basedir, protonConfig.initialize.threads);
+    InitializeThreadsCalculator calc(hwInfo.cpu(), protonConfig.basedir, protonConfig.initialize.threads);
     LOG(info, "Start initializing components: threads=%u, configured=%u",
         calc.num_threads(), protonConfig.initialize.threads);
     _initDocumentDbsInSequence = (calc.num_threads() == 1);