Bug ID: JDK-8289822 G1: Make concurrent mark code owner of TAMSes

JDK-8289822 : G1: Make concurrent mark code owner of TAMSes

Type: Enhancement
Component: hotspot
Sub-Component: gc
Affected Version: 20

Priority: P4
Status: Resolved
Resolution: Fixed

Submitted: 2022-07-06
Updated: 2024-03-27
Resolved: 2024-03-19

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JDK 23
23 b15Fixed

Related Reports

Blocks :	JDK-8210708 - Use single mark bitmap in G1
Blocks :	JDK-8290814 - Hide G1RootRegions behind G1ConcurrentMark
Blocks :	JDK-8290357 - Drop HeapRegion::marked_bytes()
Relates :	JDK-7127707 - G1: Checkpoint heap regions at start of concurrent marking to ignore heap expansions
Relates :	JDK-8290366 - Remove unused during_conc_mark parameter in HeapRegion::note_self_forwarding_removal_start
Relates :	JDK-8328879 - G1: Some gtests modify global state crashing the JVM during GC after JDK-8289822

Description

Currently HeapRegion "owns" the top_at_mark_start (TAMS) member, it is placed within that class.

As such uses have bled all over the place (particular in log messages).

However TAMS is a temporary value only needed for marking - so similar to current marked live bytes it should be managed there.

Comments

Hi, Witnessed a slowdebug jvm crash on linux-aarch64 after this change: https://bugs.openjdk.org/browse/JDK-8328879

25-03-2024

Changeset: f1c69cca Author: Thomas Schatzl <tschatzl@openjdk.org> Date: 2024-03-19 10:31:47 +0000 URL: https://git.openjdk.org/jdk/commit/f1c69ccadb83306d1bb4860ff460a253af99643c

19-03-2024

A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/18150 Date: 2024-03-07 10:31:27 +0000

07-03-2024