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Enhancement
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Resolution: Fixed
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P4
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11, 13, 14
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b19
Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build |
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JDK-8233119 | 13u-cpu | Aleksey Shipilev | P4 | Resolved | Fixed | master |
JDK-8232971 | 13.0.2 | Aleksey Shipilev | P4 | Resolved | Fixed | b03 |
JDK-8232969 | 11.0.6 | Aleksey Shipilev | P4 | Resolved | Fixed | b01 |
See here:
https://stackoverflow.com/a/58292061/2613885
This is arguably the UX bug: users expect low latency, but may not be aware that additional configuration is needed for GCs to perform well in those conditions. Epsilon already enables LSM, and should warn about Xms/Xmx/AlwaysPreTouch config too. It cannot adjust these settings, though, because it would affect startup time -- users would have to opt-in.
Sample patch:
http://cr.openjdk.java.net/~shade/8232051/webrev.01/
Emits these warnings:
[0.001s][warning][gc] Consider setting -Xms equal to -Xmx to avoid resizing hiccups
[0.001s][warning][gc] Consider adding -XX:+AlwaysPreTouch to avoid memory commit hiccups
These warnings can be shunned by overriding the default logging level with -Xlog:gc=error.
https://stackoverflow.com/a/58292061/2613885
This is arguably the UX bug: users expect low latency, but may not be aware that additional configuration is needed for GCs to perform well in those conditions. Epsilon already enables LSM, and should warn about Xms/Xmx/AlwaysPreTouch config too. It cannot adjust these settings, though, because it would affect startup time -- users would have to opt-in.
Sample patch:
http://cr.openjdk.java.net/~shade/8232051/webrev.01/
Emits these warnings:
[0.001s][warning][gc] Consider setting -Xms equal to -Xmx to avoid resizing hiccups
[0.001s][warning][gc] Consider adding -XX:+AlwaysPreTouch to avoid memory commit hiccups
These warnings can be shunned by overriding the default logging level with -Xlog:gc=error.
- backported by
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JDK-8232969 Epsilon should warn about Xms/Xmx/AlwaysPreTouch configuration
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- Resolved
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JDK-8232971 Epsilon should warn about Xms/Xmx/AlwaysPreTouch configuration
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- Resolved
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JDK-8233119 Epsilon should warn about Xms/Xmx/AlwaysPreTouch configuration
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- Resolved
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- relates to
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JDK-8347256 Epsilon: Demote heap size and AlwaysPreTouch warnings to info level
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- Resolved
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