8369346: Remove default value of and deprecate the MaxRAM flag

[jsikstro]

Hello,

Please see the CSR for a more detailed explanation and specific information regarding the deprecation of the flag. To summarize, the JVM is well-equiped to detect system memory and handle potential truncation errors (see JDK-8367413 ), making MaxRAM largely redundant. Removing the default value from MaxRAM mainly impacts systems with more memory than the default (128GB on 64-bit systems and 4GB on 32-bit systems) that are running with -XX:-UseCompressedOops or -XX:+UseZGC, which disable compressed oops. We recommend users to use well-supported flags such as -Xms and -Xmx to influence heap sizing instead.

MaxRAM is used to a very small extent to influence memory allocation in JDK tests, where MaxRAMPercentage is much more common. When MaxRAM is eventually obsoleted, the few affected tests will need to be updated or use alternative flags.

Testing:

• Oracle's tier1-8

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change requires CSR request JDK-8369347 to be approved

Issues

• JDK-8369346: Remove default value of and deprecate the MaxRAM flag (Enhancement - P4)
• JDK-8369347: Remove default value of and deprecate the MaxRAM flag (CSR)

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Leo Korinth (@lkorinth - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

@jsikstro This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8369346: Remove default value of and deprecate the MaxRAM flag

Reviewed-by: ayang, lkorinth

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[openjdk]

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[jsikstro]

/label remove graal
/label add hotspot-gc

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@jsikstro
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@jsikstro
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[mlbridge]

Webrevs

• 02: Full - Incremental (905554ab)
• 01: Full - Incremental (03188828)
• 00: Full (c9b672f6)

[lkorinth]

Looks good to me!

[jsikstro]

Thank you for the reviews! @albertnetymk @lkorinth
/integrate

[openjdk]

Going to push as commit 6964ced.
Since your change was applied there have been 4 commits pushed to the master branch:

• 4a0200c: 8367561: Getting some "header" property from a file:// URL causes a file descriptor leak
• 3cbcda5: 8359978: Test javax/net/ssl/SSLSocket/Tls13PacketSize.java failed again with java.net.SocketException: An established connection was aborted by the software in your host machine
• 78f1c44: 8370678: Update the Problemlisting for java/awt/Mixing/AWT_Mixing/OpaqueOverlapping.java
• ... and 1 more: https://git.openjdk.org/jdk/compare/d8515f084dcd537ccad98f9b15f257baeffae222...master

Your commit was automatically rebased without conflicts.

[openjdk]

@jsikstro Pushed as commit 6964ced.

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