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    Enhancement 
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    Resolution: Fixed
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     P4 P4
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    21, 23, 24
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        b06
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        aarch64
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        generic
| Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build | 
|---|---|---|---|---|---|---|
| JDK-8350016 | 24.0.2 | Liming Liu | P4 | Resolved | Fixed | b01 | 
                    This ticket is to update the default value of CodeEntryAlignment from 64 to 32 for both Ampere-1A and 1B.
GCC uses 32 for both Ampere-1A [1] and 1B [2]. The microbenchmark CodeCacheStress also shows that the frontend stall can be reduced by 21% if CodeEntryAlignment changes from 64 to 32 regardless of CodeCacheSegmentSize being 64 or 128.
[1] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=590a06afbf0e96813b5879742f38f3665512c854;hp=5ba25973e2f403ee48af2ba579af5017b2f650fb
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=cbf2369f3b545e0187fe2e659c764fabf75bb479;hp=99d114c15523e0bfe7a89ef1947f82eb5ff0260b
GCC uses 32 for both Ampere-1A [1] and 1B [2]. The microbenchmark CodeCacheStress also shows that the frontend stall can be reduced by 21% if CodeEntryAlignment changes from 64 to 32 regardless of CodeCacheSegmentSize being 64 or 128.
[1] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=590a06afbf0e96813b5879742f38f3665512c854;hp=5ba25973e2f403ee48af2ba579af5017b2f650fb
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=cbf2369f3b545e0187fe2e659c764fabf75bb479;hp=99d114c15523e0bfe7a89ef1947f82eb5ff0260b
- backported by
- 
                    JDK-8350016 Update the default value of CodeEntryAlignment for Ampere-1A and 1B -           
- Resolved
 
-         
- relates to
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                    JDK-8339573 Update CodeCacheSegmentSize and CodeEntryAlignment for ARM -           
- Resolved
 
-         
- links to
- 
                     Commit(master)
        openjdk/jdk24u/010833df Commit(master)
        openjdk/jdk24u/010833df
- 
                     Commit(master)
        openjdk/jdk/89ee1a55 Commit(master)
        openjdk/jdk/89ee1a55
- 
                     Review(master)
        openjdk/jdk21u-dev/1411 Review(master)
        openjdk/jdk21u-dev/1411
- 
                     Review(master)
        openjdk/jdk24u/70 Review(master)
        openjdk/jdk24u/70
- 
                     Review(master)
        openjdk/jdk/22134 Review(master)
        openjdk/jdk/22134
             (2 links to)