From 4db2985bc090502a7851414a3cd3dff2784d3dd5 Mon Sep 17 00:00:00 2001
From: Carlos Segarra <carlos@carlossegarra.com>
Date: Tue, 30 Nov 2021 17:11:18 +0000
Subject: [PATCH] allow setting the scheduling policy from an environment
 variable

---
 src/scheduler/Scheduler.cpp     | 5 +++++
 src/util/config.cpp             | 2 ++
 tests/test/util/test_config.cpp | 4 ++++
 3 files changed, 11 insertions(+)

diff --git a/src/scheduler/Scheduler.cpp b/src/scheduler/Scheduler.cpp
index f521fcd7e..036bd0363 100644
--- a/src/scheduler/Scheduler.cpp
+++ b/src/scheduler/Scheduler.cpp
@@ -283,6 +283,11 @@ faabric::util::SchedulingDecision Scheduler::makeSchedulingDecision(
     faabric::Message& firstMsg = req->mutable_messages()->at(0);
     std::string funcStr = faabric::util::funcToString(firstMsg, false);
 
+    // If topology hints are disabled, unset the provided topology hint
+    if (conf.useTopologyHints == "off") {
+        topologyHint = faabric::util::SchedulingTopologyHint::NORMAL;
+    }
+
     std::vector<std::string> hosts;
     if (topologyHint == faabric::util::SchedulingTopologyHint::FORCE_LOCAL) {
         // We're forced to execute locally here so we do all the messages
diff --git a/src/util/config.cpp b/src/util/config.cpp
index 633291de3..0f7b9f067 100644
--- a/src/util/config.cpp
+++ b/src/util/config.cpp
@@ -34,6 +34,7 @@ void SystemConfig::initialise()
     // Scheduling
     noScheduler = this->getSystemConfIntParam("NO_SCHEDULER", "0");
     overrideCpuCount = this->getSystemConfIntParam("OVERRIDE_CPU_COUNT", "0");
+    useTopologyHints = getEnvVar("USE_TOPOLOGY_HINTS", "off");
 
     // Worker-related timeouts (all in seconds)
     globalMessageTimeout =
@@ -100,6 +101,7 @@ void SystemConfig::print()
     SPDLOG_INFO("--- Scheduling ---");
     SPDLOG_INFO("NO_SCHEDULER               {}", noScheduler);
     SPDLOG_INFO("OVERRIDE_CPU_COUNT         {}", overrideCpuCount);
+    SPDLOG_INFO("USE_TOPOLOGY_HINTS         {}", useTopologyHints);
 
     SPDLOG_INFO("--- Timeouts ---");
     SPDLOG_INFO("GLOBAL_MESSAGE_TIMEOUT     {}", globalMessageTimeout);
diff --git a/tests/test/util/test_config.cpp b/tests/test/util/test_config.cpp
index 1c734758f..22fe6a7c3 100644
--- a/tests/test/util/test_config.cpp
+++ b/tests/test/util/test_config.cpp
@@ -22,6 +22,7 @@ TEST_CASE("Test default system config initialisation", "[util]")
 
     REQUIRE(conf.noScheduler == 0);
     REQUIRE(conf.overrideCpuCount == 0);
+    REQUIRE(conf.useTopologyHints == "off");
 
     REQUIRE(conf.globalMessageTimeout == 60000);
     REQUIRE(conf.boundTimeout == 30000);
@@ -44,6 +45,7 @@ TEST_CASE("Test overriding system config initialisation", "[util]")
 
     std::string noScheduler = setEnvVar("NO_SCHEDULER", "1");
     std::string overrideCpuCount = setEnvVar("OVERRIDE_CPU_COUNT", "4");
+    std::string useTopologyHints = setEnvVar("USE_TOPOLOGY_HINTS", "on");
 
     std::string globalTimeout = setEnvVar("GLOBAL_MESSAGE_TIMEOUT", "9876");
     std::string boundTimeout = setEnvVar("BOUND_TIMEOUT", "6666");
@@ -70,6 +72,7 @@ TEST_CASE("Test overriding system config initialisation", "[util]")
 
     REQUIRE(conf.noScheduler == 1);
     REQUIRE(conf.overrideCpuCount == 4);
+    REQUIRE(conf.useTopologyHints == "on");
 
     REQUIRE(conf.globalMessageTimeout == 9876);
     REQUIRE(conf.boundTimeout == 6666);
@@ -95,6 +98,7 @@ TEST_CASE("Test overriding system config initialisation", "[util]")
 
     setEnvVar("NO_SCHEDULER", noScheduler);
     setEnvVar("OVERRIDE_CPU_COUNT", overrideCpuCount);
+    setEnvVar("USE_TOPOLOGY_HINTS", useTopologyHints);
 
     setEnvVar("GLOBAL_MESSAGE_TIMEOUT", globalTimeout);
     setEnvVar("BOUND_TIMEOUT", boundTimeout);