[jdk17u-dev] RFR: 8350285: Shenandoah: Regression caused by ShenandoahLock under extreme contention

[Aleksey Shipilev]

On Wed, 28 May 2025 23:01:23 GMT, Daniel Huang <duke at openjdk.org> wrote:

> Backport for ShenandoahLock performance regression issue. The fix involves sleeping for a very short duration every 3 yields, with the number of yields picked through manual testing. 
> 
> Clean backport, ran GHA sanity checks and locally tested `tier1`, `tier2`, and `hotspot_gc_shenandoah`. `test/jdk/java/nio/channels/FileChannel/directio/DirectIOTest.java` sometimes fails locally, but it also sometimes failed before the fix.

Just to make sure, @robilad: @dtmhuang is from Amazon :)

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PR Comment: https://git.openjdk.org/jdk17u-dev/pull/3614#issuecomment-2931375285