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8355792: Remove expired flags in JDK 26

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Reviewed-by: coleenp, kvn
This commit is contained in:
David Holmes 2025-06-09 22:25:20 +00:00
parent d186dacdb7
commit bcf860703d
2 changed files with 3 additions and 66 deletions
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4
src/hotspot/share/runtime/arguments.cpp
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@ -528,9 +528,6 @@ static SpecialFlag const special_jvm_flags[] = {
{ "DynamicDumpSharedSpaces", JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
{ "RequireSharedSpaces", JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
{ "UseSharedSpaces", JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
#ifdef LINUX
{ "UseLinuxPosixThreadCPUClocks", JDK_Version::jdk(24), JDK_Version::jdk(25), JDK_Version::jdk(26) },
#endif
{ "LockingMode", JDK_Version::jdk(24), JDK_Version::jdk(26), JDK_Version::jdk(27) },
#ifdef _LP64
{ "UseCompressedClassPointers", JDK_Version::jdk(25), JDK_Version::jdk(26), JDK_Version::undefined() },
@ -540,7 +537,6 @@ static SpecialFlag const special_jvm_flags[] = {
// -------------- Obsolete Flags - sorted by expired_in --------------
{ "PerfDataSamplingInterval", JDK_Version::undefined(), JDK_Version::jdk(25), JDK_Version::jdk(26) },
#ifdef LINUX
{ "UseOprofile", JDK_Version::jdk(25), JDK_Version::jdk(26), JDK_Version::jdk(27) },
#endif

65
src/java.base/share/man/java.md
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@ -2917,71 +2917,12 @@ when they're used.
## Removed Java Options
These `java` options have been removed in JDK @@VERSION_SPECIFICATION@@ and using them results in an error of:
> `Unrecognized VM option` *option-name*
`-XX:RTMAbortRatio=`*abort\_ratio*
: Specifies the RTM abort ratio is specified as a percentage (%) of all
executed RTM transactions. If a number of aborted transactions becomes
greater than this ratio, then the compiled code is deoptimized. This ratio
is used when the `-XX:+UseRTMDeopt` option is enabled. The default value of
this option is 50. This means that the compiled code is deoptimized if 50%
of all transactions are aborted.
`-XX:RTMRetryCount=`*number\_of\_retries*
: Specifies the number of times that the RTM locking code is retried, when it
is aborted or busy, before falling back to the normal locking mechanism.
The default value for this option is 5. The `-XX:UseRTMLocking` option must
be enabled.
`-XX:+UseRTMDeopt`
: Autotunes RTM locking depending on the abort ratio. This ratio is specified
by the `-XX:RTMAbortRatio` option. If the number of aborted transactions
exceeds the abort ratio, then the method containing the lock is deoptimized
and recompiled with all locks as normal locks. This option is disabled by
default. The `-XX:+UseRTMLocking` option must be enabled.
`-XX:+UseRTMLocking`
: Generates Restricted Transactional Memory (RTM) locking code for all
inflated locks, with the normal locking mechanism as the fallback handler.
This option is disabled by default. Options related to RTM are available
only on x86 CPUs that support Transactional Synchronization Extensions (TSX).
RTM is part of Intel's TSX, which is an x86 instruction set extension and
facilitates the creation of multithreaded applications. RTM introduces the
new instructions `XBEGIN`, `XABORT`, `XEND`, and `XTEST`. The `XBEGIN` and
`XEND` instructions enclose a set of instructions to run as a transaction.
If no conflict is found when running the transaction, then the memory and
register modifications are committed together at the `XEND` instruction.
The `XABORT` instruction can be used to explicitly abort a transaction and
the `XTEST` instruction checks if a set of instructions is being run in a
transaction.
A lock on a transaction is inflated when another thread tries to access the
same transaction, thereby blocking the thread that didn't originally
request access to the transaction. RTM requires that a fallback set of
operations be specified in case a transaction aborts or fails. An RTM lock
is a lock that has been delegated to the TSX's system.
RTM improves performance for highly contended locks with low conflict in a
critical region (which is code that must not be accessed by more than one
thread concurrently). RTM also improves the performance of coarse-grain
locking, which typically doesn't perform well in multithreaded
applications. (Coarse-grain locking is the strategy of holding locks for
long periods to minimize the overhead of taking and releasing locks, while
fine-grained locking is the strategy of trying to achieve maximum
parallelism by locking only when necessary and unlocking as soon as
possible.) Also, for lightly contended locks that are used by different
threads, RTM can reduce false cache line sharing, also known as cache line
ping-pong. This occurs when multiple threads from different processors are
accessing different resources, but the resources share the same cache line.
As a result, the processors repeatedly invalidate the cache lines of other
processors, which forces them to read from main memory instead of their
cache.
No documented java options have been removed in JDK @@VERSION_SPECIFICATION@@.
For the lists and descriptions of options removed in previous releases see the *Removed Java Options* section in:
- [The `java` Command, Release 25](https://docs.oracle.com/en/java/javase/25/docs/specs/man/java.html)
- [The `java` Command, Release 24](https://docs.oracle.com/en/java/javase/24/docs/specs/man/java.html)
- [The `java` Command, Release 23](https://docs.oracle.com/en/java/javase/23/docs/specs/man/java.html)