supermem613 commented on code in PR #5439: URL: https://github.com/apache/incubator-gluten/pull/5439#discussion_r1589167853
########## gluten-core/src/main/java/org/apache/gluten/memory/memtarget/spark/DynamicOffHeapSizingPolicyChecker.java: ########## @@ -0,0 +1,71 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.gluten.memory.memtarget.spark; + +import org.apache.gluten.GlutenConfig; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.concurrent.atomic.AtomicLong; + +public final class DynamicOffHeapSizingPolicyChecker { + private static final Logger LOG = + LoggerFactory.getLogger(DynamicOffHeapSizingPolicyChecker.class); + private final long maxOnHeapMemoryInBytes = GlutenConfig.getConf().onHeapMemorySize(); + private final AtomicLong usedOffHeapBytes = new AtomicLong(); + + DynamicOffHeapSizingPolicyChecker() {} + + public boolean canBorrow(long size) { + if (size == 0) { + return true; + } + + long totalMemory = Runtime.getRuntime().totalMemory(); + long freeMemory = Runtime.getRuntime().freeMemory(); + long usedOnHeapBytes = (totalMemory - freeMemory); Review Comment: I see. Yes, the amount of memory that we are calculating as "committed but unused by the JVM", with the freeMemory API call, likely would be counted by the OSS as part of the RSS since the JVM likely touches those pages as they are added to the JVM heap free list. However, the counterpoint is that these pages will not see further memory access unless they are actually put to use, so if we consider them against the overall "used" quota, we are essentially leaving unused memory capacity at the table. Perhaps a good way to approach this is to add a specific config with the proposed change that optionally allows for this more aggressive use of memory. If the config is off, say, the default, we will consider totalMemory as the total used memory, not discounting the freeMemory API value. If the setting is off, we will discount the freeMemory API value as the proposed changes stand now. Thoughts? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
