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2011-06-14Improve ethread atomicsRickard Green
The ethread atomics API now also provide double word size atomics. Double word size atomics are implemented using native atomic instructions on x86 (when the cmpxchg8b instruction is available) and on x86_64 (when the cmpxchg16b instruction is available). On other hardware where 32-bit atomics or word size atomics are available, an optimized fallback is used; otherwise, a spinlock, or a mutex based fallback is used. The ethread library now performs runtime tests for presence of hardware features, such as for example SSE2 instructions, instead of requiring this to be determined at compile time. There are now functions implementing each atomic operation with the following implied memory barrier semantics: none, read, write, acquire, release, and full. Some of the operation-barrier combinations aren't especially useful. But instead of filtering useful ones out, and potentially miss a useful one, we implement them all. A much smaller set of functionality for native atomics are required to be implemented than before. More or less only cmpxchg and a membar macro are required to be implemented for each atomic size. Other functions will automatically be constructed from these. It is, of course, often wise to implement more that this if possible from a performance perspective.
2011-05-20Update copyright yearsBjörn-Egil Dahlberg
2011-05-13Merge branch 'rickard/barriers/OTP-9281' into devRickard Green
* rickard/barriers/OTP-9281: Silence warnings Fix build with hipe on amd64 Reduce number of atomic ops Use 32-bit atomic for port snapshot Remove pointless erts_ports_alive variable Ensure quick break Ensure that all rehashing information are seen when done Ensure that stack updates are seen when stack is released Add needed barriers for write_concurrency tables Homogenize memory barriers on atomics
2011-05-11Homogenize memory barriers on atomicsRickard Green
Atomic operations with specified barriers have specified barrier semantics. Set and read operations have undefined barrier semantics. All other atomic operations implied full memory barriers, except when using the libatomic_ops library and the tilera atomics api. Some code in the runtime system assumed that all operations used (except for set, read and specified) implied full memory barriers. The use of the libatomic_ops library and the tilera atomics api have therefore been modified to behave as the other implementations. Some atomic operations with specified barrier semantics on sparc32 have also been been relaxed in this commit.
2011-05-06erts_printf %R for relative ets-terms in halfword-vmSverker Eriksson
Conflicts: erts/emulator/beam/erl_printf_term.c
2011-03-11Update copyright yearsBjörn-Egil Dahlberg
2011-03-08The emulator could get into a state where it didn't check for I/O.Rickard Green
2010-12-16Use 32-bit atomic for uaflgs in thread specific eventsRickard Green
2010-12-15Use 32-bit atomics for mutex and rwmutex flagsRickard Green
2010-12-15Use 32-bit atomics for eventsRickard Green
2010-12-15Add support for 32-bit atomicsRickard Green
2010-12-14Move atomic API into own filesRickard Green
2010-12-14Add support for 64-bit atomics on WindowsRickard Green
2010-12-14Remove unused ethread time functionalityRickard Green
2010-12-11Introduce ethr_sint_t and use it for atomicsRickard Green
The atomic memory operations interface used the 'long' type and assumed that it was of the same size as 'void *'. This is true on most platforms, however, not on Windows 64.
2010-12-03Merge branch 'rickard/rwmutex-bug/OTP-8925' into devRickard Green
* rickard/rwmutex-bug/OTP-8925: Use correct argument types on rwlock_wake_set_flags()
2010-12-02Use correct argument types on rwlock_wake_set_flags()Rickard Green
2010-12-01Merge branch 'rickard/rwmutex-bug/OTP-8925' into devRickard Green
* rickard/rwmutex-bug/OTP-8925: Miscellaneous rwmutex bug fixes and improvements Don't use more reader groups than schedulers New test suite containing stress tests of the rwmutex implementation Conflicts: erts/emulator/beam/erl_init.c
2010-12-01Miscellaneous rwmutex bug fixes and improvementsRickard Green
The ERTS internal rwlock implementation could get into an inconsistent state. This bug was very seldom triggered, but could be during heavy contention. The bug was introduced in R14B (erts-5.8.1). The bug was most likely to be triggered when using the read_concurrency option on an ETS table that was frequently accessed from multiple processes doing lots of writes and reads. That is, in a situation where you typically don't want to use the read_concurrency option in the first place.
2010-11-22Merge branch 'ta/fix-ethread-void-return' into devRickard Green
* ta/fix-ethread-void-return: ethread: do not return from void ethr_atomic_set_relb OTP-8944
2010-10-29Allow usage of libatomic_ops when other compilers than gcc are usedRickard Green
2010-10-29ethread: do not return from void ethr_atomic_set_relbTuncer Ayaz
Reported-by: Patrick Baggett <[email protected]>
2010-09-10Merge branch 'sv/ethread-atomic-mips' into devRickard Green
* sv/ethread-atomic-mips: add MIPS architecture to GCC ethread atomics support
2010-09-08Increase spincount with many schedulersRickard Green
2010-09-07add MIPS architecture to GCC ethread atomics supportSteve Vinoski
Gcc for MIPS supports immediate atomic gets and sets, and also supports a working __sync_synchronize() for gcc 4.2 and greater.
2010-08-30Implement automatic detection of CPU topology on WindowsRickard Green
The CPU topology is now automatically detected on Windows systems with less than 33 logical processors. The runtime system will now, also on Windows, by default bind schedulers to logical processors using the 'default_bind' bind type if the amount of schedulers is at least equal to the amount of logical processors configured, binding of schedulers is supported, and a CPU topology is available at startup.
2010-08-18Make it possible to reread and update detected CPU informationRickard Green
Calling erlang:system_info/1 with the new argument 'update_cpu_info' will make the runtime system reread and update the internally stored CPU information. For more information see the documentation of erlang:system_info(update_cpu_info).
2010-08-10Rewrite ethread libraryRickard Green
Large parts of the ethread library have been rewritten. The ethread library is an Erlang runtime system internal, portable thread library used by the runtime system itself. Most notable improvement is a reader optimized rwlock implementation which dramatically improve the performance of read-lock/read-unlock operations on multi processor systems by avoiding ping-ponging of the rwlock cache lines. The reader optimized rwlock implementation is used by miscellaneous rwlocks in the runtime system that are known to be read-locked frequently, and can be enabled on ETS tables by passing the `{read_concurrency, true}' option upon table creation. See the documentation of `ets:new/2' for more information. The ethread library can now also use the libatomic_ops library for atomic memory accesses. This makes it possible for the Erlang runtime system to utilize optimized atomic operations on more platforms than before. Use the `--with-libatomic_ops=PATH' configure command line argument when specifying where the libatomic_ops installation is located. The libatomic_ops library can be downloaded from: http://www.hpl.hp.com/research/linux/atomic_ops/ The changed API of the ethread library has also caused modifications in the Erlang runtime system. Preparations for the to come "delayed deallocation" feature has also been done since it depends on the ethread library. Note: When building for x86, the ethread library will now use instructions that first appeared on the pentium 4 processor. If you want the runtime system to be compatible with older processors (back to 486) you need to pass the `--enable-ethread-pre-pentium4-compatibility' configure command line argument when configuring the system.
2010-06-01OTP-8661 Enable writer preferred pthread read/write locks on LinuxRickard Green
Writer preferred pthread read/write locks has been enabled on Linux.
2010-06-01OTP-8660 Increase atomic fallback locksRickard Green
The number of spinlocks used when implementing atomic fall-backs when no native atomic implementation is available has been increased from 16 to 1024.
2010-06-01OTP-8659 Add ethread support for gcc atomicsRickard Green
Support for using gcc's built-in functions for atomic memory access has been added. This functionallity will be used if available and no other native atomic implementation in ERTS is available.
2010-06-01OTP-8658 Add missing memory barriers in erts_poll()Rickard Green
Missing memory barriers in erts_poll() could cause the runtime system to hang indefinitely.
2010-02-08OTP-8412 Fixed numerous compiler warnings generated by gcc 4.4.1 andRickard Green
tile-cc 2.0.1.78377 when compiling the runtime system.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP