OpenJDK / jdk / jdk
changeset 39407:2e75eb109278
8152438: Threads may do significant work out of the non-shared overflow buffer
Summary: Before processing an element in the non-shared overflow buffer, try to push it into the local shared buffer to keep it full.
Reviewed-by: jmasa, ehelin, sjohanss
| author | tschatzl |
|---|---|
| date | Wed, 22 Jun 2016 10:34:01 +0200 |
| parents | 314741ca98d5 |
| children | 598092582b4e |
| files | hotspot/src/share/vm/gc/g1/g1ParScanThreadState.cpp hotspot/src/share/vm/gc/shared/taskqueue.hpp hotspot/src/share/vm/gc/shared/taskqueue.inline.hpp |
| diffstat | 3 files changed, 11 insertions(+), 2 deletions(-) [+] |
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--- a/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.cpp Tue Jun 21 19:29:39 2016 -0400 +++ b/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.cpp Wed Jun 22 10:34:01 2016 +0200 @@ -137,7 +137,9 @@ do { // Drain the overflow stack first, so other threads can steal. while (_refs->pop_overflow(ref)) { - dispatch_reference(ref); + if (!_refs->try_push_to_taskqueue(ref)) { + dispatch_reference(ref); + } } while (_refs->pop_local(ref)) {
--- a/hotspot/src/share/vm/gc/shared/taskqueue.hpp Tue Jun 21 19:29:39 2016 -0400 +++ b/hotspot/src/share/vm/gc/shared/taskqueue.hpp Wed Jun 22 10:34:01 2016 +0200 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -330,6 +330,8 @@ // Push task t onto the queue or onto the overflow stack. Return true. inline bool push(E t); + // Try to push task t onto the queue only. Returns true if successful, false otherwise. + inline bool try_push_to_taskqueue(E t); // Attempt to pop from the overflow stack; return true if anything was popped. inline bool pop_overflow(E& t);
--- a/hotspot/src/share/vm/gc/shared/taskqueue.inline.hpp Tue Jun 21 19:29:39 2016 -0400 +++ b/hotspot/src/share/vm/gc/shared/taskqueue.inline.hpp Wed Jun 22 10:34:01 2016 +0200 @@ -103,6 +103,11 @@ return true; } +template <class E, MEMFLAGS F, unsigned int N> +inline bool OverflowTaskQueue<E, F, N>::try_push_to_taskqueue(E t) { + return taskqueue_t::push(t); +} + // pop_local_slow() is done by the owning thread and is trying to // get the last task in the queue. It will compete with pop_global() // that will be used by other threads. The tag age is incremented