8283199: Linux os::cpu_microcode_revision() stalls cold startup

[shipilev]

Unclean backport to fix the startup time regression.

The backport is not clean, because JDK-8238161 is not present in JDK 11, and thus we have fopen instead of os::fopen in these hunks. I changed the code back to fopen to be consistent with the rest of JDK 11.

Verified the startup time improves, using the scripts from the issue.

# Before
real	0m0.081s
real	0m0.081s
real	0m0.081s

# After
real	0m0.062s
real	0m0.062s
real	0m0.062s

Additional testing:

• Linux x86_64 fastdebug tier1

---

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

Issue

• JDK-8283199: Linux os::cpu_microcode_revision() stalls cold startup

Reviewers

• Thomas Stuefe (@tstuefe - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk11u-dev pull/1471/head:pull/1471
$ git checkout pull/1471

Update a local copy of the PR:
$ git checkout pull/1471
$ git pull https://git.openjdk.org/jdk11u-dev pull/1471/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 1471

View PR using the GUI difftool:
$ git pr show -t 1471

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk11u-dev/pull/1471.diff

[bridgekeeper]

👋 Welcome back shade! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 00: Full (4a44640e)

[shipilev]

Any takers? :)

[shipilev]

Any takers? :)

Friendly reminder :)

[tstuefe]

Good.

[openjdk]

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

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

8283199: Linux os::cpu_microcode_revision() stalls cold startup

Reviewed-by: stuefe

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 49 new commits pushed to the master branch:

• b7b00f7: 8296108: (tz) Update Timezone Data to 2022f
• e3eccbc: 8294307: ISO 4217 Amendment 173 Update
• 954a6e4: 8286872: Refactor add/modify notification icon (TrayIcon)
• f2f7be9: 8202836: [macosx] test java/awt/Graphics/TextAAHintsTest.java fails
• 8a40a9c: 8274029: Remove jtreg tag manual=yesno for java/awt/print/Dialog/DialogOrient.java
• 7e0603f: 8274456: Remove jtreg tag manual=yesno java/awt/print/PrinterJob/PageDialogTest.java
• 5d28a71: 8295714: GHA ::set-output is deprecated and will be removed
• d2af653: 8295872: [PPC64] JfrGetCallTrace: Need pc == nullptr check before frame constructor
• 3b7f045: 8296480: java/security/cert/pkix/policyChanges/TestPolicy.java is failing
• 338f9af: 8255439: System Tray icons get corrupted when Windows scaling changes
• ... and 39 more: https://git.openjdk.org/jdk11u-dev/compare/37d3bbd6033778547f32640243dc3f281d424531...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[shipilev]

Thank you, marked for approval.

[shipilev]

Got the push approval.

/integrate

[openjdk]

Going to push as commit 5d9c09b.
Since your change was applied there have been 57 commits pushed to the master branch:

• 7e6c47d: 8294740: Add cgroups keyword to TestDockerBasic.java
• 9eac68b: 8293540: [Metrics] Incorrectly detected resource limits with additional cgroup fs mounts
• 7706fa8: 8293472: Incorrect container resource limit detection if manual cgroup fs mounts present
• 4ee685a: 8029633: Raw inner class constructor ref should not perform diamond inference
• 1f17371: 8296652: Restore windows aarch64 fixpath patch that was removed in 8239708
• 5043784: 8256109: Create implementation for NSAccessibilityButton protocol
• 55354dd: 8264666: Change implementation of safeAdd/safeMult in the LCMSImageLayout class
• 1549bb1: 8288302: Shenandoah: SIGSEGV in vm maybe related to jit compiling xerces
• b7b00f7: 8296108: (tz) Update Timezone Data to 2022f
• e3eccbc: 8294307: ISO 4217 Amendment 173 Update
• ... and 47 more: https://git.openjdk.org/jdk11u-dev/compare/37d3bbd6033778547f32640243dc3f281d424531...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 5d9c09b.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.