Details
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Bug
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Resolution: Fixed
-
P1
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8
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inapplicable
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Verified
Description
Just saw:
http://download.java.net/jdk8/docs/technotes/tools/unix/java.html
and noticed a few errors:
-Xboundthreads
Binds user-level threads to kernel threads.
There is no such option. There is a -XX:+UseBoundThreads but it was only relevant on Solaris and defaults to true
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep boundthreads
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep BoundThreads
bool UseBoundThreads = true {product}
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
---
-XX:+UseBiasedLocking
By default, this option is disabled and biased locking is not used.
Incorrect - biased locking is on by default.
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep UseBiasedLocking
bool UseBiasedLocking = true {product}
---
-XX:+UseMembar
Enables issuing of membars on thread state transitions. This option is disabled by default on all platforms except Power PC and ARM servers, where it is enabled. To disable issuing of membars on thread state transitions for Power PC and ARM, specify -XX:-UseMembar.
Mostly accurate but if you turn it off on multi-processor arm/ppc then you are likely to crash the VM. (And not sure why we mention PPC here as it is only supported in SE-Embedded.)
---
-XX:+TieredCompilation
Enables the use of tiered compilation. By default, this option is disabled and tiered compilation is not used.
Pretty sure that tiered is now on by default on x86 and sparc at least.
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep TieredCompilation
bool TieredCompilation = true {pd product}
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
----
The following -X options are documented but are not reported in response to "java -X"
-Xcomp
-Xdebug
-Xinternalversion
-Xmaxjitcodesize
-Xmn
-Xusealtsigs
-Xverify
----
Typo: loader constraints recoding -> loader constraints recording
----
Finally some options pertain only to a specific feature eg DoEscapeAnalysis only applies to the Server VM.
http://download.java.net/jdk8/docs/technotes/tools/unix/java.html
and noticed a few errors:
-Xboundthreads
Binds user-level threads to kernel threads.
There is no such option. There is a -XX:+UseBoundThreads but it was only relevant on Solaris and defaults to true
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep boundthreads
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep BoundThreads
bool UseBoundThreads = true {product}
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
---
-XX:+UseBiasedLocking
By default, this option is disabled and biased locking is not used.
Incorrect - biased locking is on by default.
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep UseBiasedLocking
bool UseBiasedLocking = true {product}
---
-XX:+UseMembar
Enables issuing of membars on thread state transitions. This option is disabled by default on all platforms except Power PC and ARM servers, where it is enabled. To disable issuing of membars on thread state transitions for Power PC and ARM, specify -XX:-UseMembar.
Mostly accurate but if you turn it off on multi-processor arm/ppc then you are likely to crash the VM. (And not sure why we mention PPC here as it is only supported in SE-Embedded.)
---
-XX:+TieredCompilation
Enables the use of tiered compilation. By default, this option is disabled and tiered compilation is not used.
Pretty sure that tiered is now on by default on x86 and sparc at least.
bussund0416 ~ > /java/re/jdk/8/latest/binaries/linux-i586/bin/java -XX:+PrintFlagsFinal -version | grep TieredCompilation
bool TieredCompilation = true {pd product}
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b126)
Java HotSpot(TM) Server VM (build 25.0-b67, mixed mode)
----
The following -X options are documented but are not reported in response to "java -X"
-Xcomp
-Xdebug
-Xinternalversion
-Xmaxjitcodesize
-Xmn
-Xusealtsigs
-Xverify
----
Typo: loader constraints recoding -> loader constraints recording
----
Finally some options pertain only to a specific feature eg DoEscapeAnalysis only applies to the Server VM.
Attachments
Issue Links
- relates to
-
JDK-8039071 java -X options do not list all documented -X options
- Closed