RFR: 8247740: Inline derived CollectedHeap access for G1 and ParallelGC
per.liden at oracle.com
Tue Jun 23 06:56:48 UTC 2020
On 6/17/20 2:32 PM, Kim Barrett wrote:
> Please review this change to derived CollectedHeap access for the
> various collectors. Most of the collectors have a heap() function
> that returns the derived CollectedHeap object, with the definitions of
> these functions being nearly identical. This change adds a helper
> function in CollectedHeap for use by these derived heap() functions.
> This change also inlines the heap() functions for G1 and ParallelGC.
> These functions have a very simple definition in a release build.
> Since both of these collectors have calls in relatively performance
> critical places, inlining should be (a little bit) helpful, though I
> haven't tried to measure it. In some cases it may be better to get
> the heap once and cache it in a variable or data member; indeed,
> that's often done, but not always, and tracking down all the cases
> that matter isn't a small task.
> This change only does the inlining for G1 and ParallelGC. Performance
> of Serial and Epsilon is less critical, and ZGC does a good job of
> avoiding hot calls. Shenandoah doesn't have a corresponding function;
> it seems to have not conformed to the JDK-8077415 change.
> mach5 tier1
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