Add config control over feeding niceness

4 files changed, 14 insertions, 2 deletions

diff --git a/searchcore/src/vespa/searchcore/config/proton.def b/searchcore/src/vespa/searchcore/config/proton.def
index ffd9db2f58b..c8fac7fb40e 100644
--- a/searchcore/src/vespa/searchcore/config/proton.def
+++ b/searchcore/src/vespa/searchcore/config/proton.def
@@ -483,6 +483,11 @@ hwinfo.cpu.cores int default = 0 restart
 ## See shared_threading_service_config.cpp for details on how the thread pool sizes are calculated.
 feeding.concurrency double default = 0.2 restart
 
+## A number between 0.0 and 1.0 telling how nice the feed and background threads shall be.
+## A value of 0.0, which is default, means 'not any nicer than anyone else'.
+## The scale from 0.0 to 1.0 is not linear. It is OS specific. A large number means 'not less nice than a lower number'.
+feeding.niceness double default = 0.0 restart
+
 ## Maximum number of pending tasks for the master thread in each document db.
 ##
 ## This limit is only considered when executing tasks for handling external feed operations.
diff --git a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service.cpp b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service.cpp
index 86db96a20ac..5f522bfaffc 100644
--- a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service.cpp
@@ -6,6 +6,7 @@
 #include <vespa/vespalib/util/cpu_usage.h>
 #include <vespa/vespalib/util/sequencedtaskexecutor.h>
 #include <vespa/vespalib/util/size_literals.h>
+#include <vespa/vespalib/util/nice.h>
 
 using vespalib::CpuUsage;
 using vespalib::steady_time;
@@ -24,7 +25,7 @@ SharedThreadingService::SharedThreadingService(const SharedThreadingServiceConfi
                                                               CpuUsage::wrap(proton_warmup_executor, CpuUsage::Category::COMPACT),
                                                               cfg.shared_task_limit())),
       _shared(std::make_shared<vespalib::BlockingThreadStackExecutor>(cfg.shared_threads(), 128_Ki,
-                                                                      cfg.shared_task_limit(), proton_shared_executor)),
+                                                                      cfg.shared_task_limit(), vespalib::be_nice(proton_shared_executor, cfg.feeding_niceness()))),
       _field_writer(),
       _invokeService(std::max(vespalib::adjustTimeoutByDetectedHz(1ms),
                               cfg.field_writer_config().reactionTime())),
@@ -33,7 +34,7 @@ SharedThreadingService::SharedThreadingService(const SharedThreadingServiceConfi
       _clock(_invokeService.nowRef())
 {
     const auto& fw_cfg = cfg.field_writer_config();
-    _field_writer = vespalib::SequencedTaskExecutor::create(CpuUsage::wrap(proton_field_writer_executor, CpuUsage::Category::WRITE),
+    _field_writer = vespalib::SequencedTaskExecutor::create(vespalib::be_nice(CpuUsage::wrap(proton_field_writer_executor, CpuUsage::Category::WRITE), cfg.feeding_niceness()),
                                                             cfg.field_writer_threads(),
                                                             fw_cfg.defaultTaskLimit(),
                                                             fw_cfg.is_task_limit_hard(),
diff --git a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.cpp b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.cpp
index 002ac508b4a..50ef5039e75 100644
--- a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.cpp
@@ -12,11 +12,13 @@ SharedThreadingServiceConfig::SharedThreadingServiceConfig(uint32_t shared_threa
                                                            uint32_t shared_task_limit_in,
                                                            uint32_t warmup_threads_in,
                                                            uint32_t field_writer_threads_in,
+                                                           double feeding_niceness_in,
                                                            const ThreadingServiceConfig& field_writer_config_in)
     : _shared_threads(shared_threads_in),
       _shared_task_limit(shared_task_limit_in),
       _warmup_threads(warmup_threads_in),
       _field_writer_threads(field_writer_threads_in),
+      _feeding_niceness(feeding_niceness_in),
       _field_writer_config(field_writer_config_in)
 {
 }
@@ -61,6 +63,7 @@ SharedThreadingServiceConfig::make(const proton::SharedThreadingServiceConfig::P
     return proton::SharedThreadingServiceConfig(shared_threads, shared_threads * 16,
                                                 derive_warmup_threads(cpu_info),
                                                 field_writer_threads,
+                                                cfg.feeding.niceness,
                                                 ThreadingServiceConfig::make(cfg));
 }
 
diff --git a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.h b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.h
index 5a2468ca1ab..add592f463d 100644
--- a/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.h
+++ b/searchcore/src/vespa/searchcore/proton/server/shared_threading_service_config.h
@@ -20,6 +20,7 @@ private:
     uint32_t _shared_task_limit;
     uint32_t _warmup_threads;
     uint32_t _field_writer_threads;
+    double   _feeding_niceness;
     ThreadingServiceConfig _field_writer_config;
 
 public:
@@ -27,6 +28,7 @@ public:
                                  uint32_t shared_task_limit_in,
                                  uint32_t warmup_threads_in,
                                  uint32_t field_writer_threads_in,
+                                 double feed_niceness_in,
                                  const ThreadingServiceConfig& field_writer_config_in);
 
     static SharedThreadingServiceConfig make(const ProtonConfig& cfg, const HwInfo::Cpu& cpu_info);
@@ -35,6 +37,7 @@ public:
     uint32_t shared_task_limit() const { return _shared_task_limit; }
     uint32_t warmup_threads() const { return _warmup_threads; }
     uint32_t field_writer_threads() const { return _field_writer_threads; }
+    double feeding_niceness() const { return _feeding_niceness; }
     const ThreadingServiceConfig& field_writer_config() const { return _field_writer_config; }
 };