JDK-8192070 : Deoptimization performance degraded on x86 after AVX-512 support was added
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 9,10
  • Priority: P3
  • Status: Open
  • Resolution: Unresolved
  • CPU: x86
  • Submitted: 2017-11-29
  • Updated: 2020-05-07
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
Other
tbdUnresolved
Related Reports
Relates :  
JDK-8188133 - C2: Static field accesses in clinit can trigger deoptimizations
Description
Deoptimization performance degraded on x86 after AVX-512 support was added.

Test case reported in JDK-8188133 triggers pathological behavior (continuous deoptimization) in the JVM and it's >50% slower in 9 vs 8.

Profiling shows that deoptimization-related logic slowed down 2-3x and dominated by vframeArray::fill_in() where callee-saved registers are copied.
Comments
ILW = performance degradation with deoptimization; with x86 after AVX-512 support, for deoptimization; no workaround = MMH = P3
30-11-2017