Optimize number of max processes used for computing and limit number of thread running load_data_in_thread()

For max processes used for computing, we need to make sure every summary directory has a process to load data. We also should not use too many processes to avoid system problems (eg. out of memory). So we calc the max processes cnt in _calc_default_max_processes_cnt

For _load_data_in_thread_wrapper, because self._load_data_in_thread() will create process pool when loading files, we can not afford to run multiple self._load_data_in_thread() simultaneously. So we use a lock to make sure that only one self._load_data_in_thread() is running.

mindinsight/conf/constants.py

@@ -14,8 +14,37 @@
 # ============================================================================
 """Constants module for mindinsight settings."""
 import logging
+import math
 import os
 
+
+_DEFAULT_MAX_THREADS_COUNT = 15
+
+
+def _calc_default_max_processes_cnt():
+    """Calc default processes count."""
+
+    # We need to make sure every summary directory has a process to load data.
+    min_cnt = _DEFAULT_MAX_THREADS_COUNT
+    # Do not use too many processes to avoid system problems (eg. out of memory).
+    max_cnt = 45
+    used_cpu_ratio = 0.75
+
+    cpu_count = os.cpu_count()
+    if cpu_count is None:
+        return min_cnt
+
+    processes_cnt = math.floor(cpu_count * used_cpu_ratio)
+
+    if processes_cnt < min_cnt:
+        return min_cnt
+
+    if processes_cnt > max_cnt:
+        return max_cnt
+
+    return processes_cnt
+
+
 ####################################
 # Global default settings.
 ####################################
@@ -48,8 +77,8 @@ API_PREFIX = '/v1/mindinsight'
 ####################################
 # Datavisual default settings.
 ####################################
-MAX_THREADS_COUNT = 15
-MAX_PROCESSES_COUNT = max(os.cpu_count() or 0, 15)
+MAX_THREADS_COUNT = _DEFAULT_MAX_THREADS_COUNT
+MAX_PROCESSES_COUNT = _calc_default_max_processes_cnt()
 
 MAX_TAG_SIZE_PER_EVENTS_DATA = 300
 DEFAULT_STEP_SIZES_PER_TAG = 500

mindinsight/datavisual/data_transform/data_manager.py

@@ -831,6 +831,11 @@ class DataManager:
         self._detail_cache = _DetailCacheManager(loader_generators)
         self._brief_cache = _BriefCacheManager()
 
+        # This lock is used to make sure that only one self._load_data_in_thread() is running.
+        # Because self._load_data_in_thread() will create process pool when loading files, we can not
+        # afford to run multiple self._load_data_in_thread() simultaneously (will create too many processes).
+        self._load_data_lock = threading.Lock()
+
     @property
     def summary_base_dir(self):
         """Get summary base dir."""
@@ -886,7 +891,8 @@ class DataManager:
     def _load_data_in_thread_wrapper(self):
         """Wrapper for load data in thread."""
         try:
-            self._load_data_in_thread()
+            with self._load_data_lock:
+                self._load_data_in_thread()
         except MindInsightException as exc:
             # Not raising the exception here to ensure that data reloading does not crash.
             logger.warning(exc.message)