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path: root/erts/emulator/test/scheduler_SUITE.erl
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2014-02-24further enhancements for dirty schedulersSteve Vinoski
Add support for setting the number of dirty CPU schedulers online via erlang:system_flag/2. Assuming the emulator is built with dirty schedulers enabled, the number of dirty CPU schedulers online may not be less than 1, nor greater than the number of dirty CPU schedulers available, nor greater than the number of normal schedulers online. Dirty CPU scheduler threads that are taken offline via system_flag/2 are suspended. The number of dirty CPU schedulers online may be adjusted independently of the number of normal schedulers online, but if system_flag/2 is used to set the number of normal schedulers online to a value less than the current number of normal schedulers online, the number of dirty CPU schedulers online is decreased proportionally. Likewise, if the number of normal schedulers online is increased, the number of dirty CPU schedulers online is increased proportionally. For example, if 8 normal schedulers and 4 dirty CPU schedulers are online, and system_flag/2 is called to set the number of normal schedulers online to 4, the number of dirty CPU schedulers online is also decreased by half, to 2. Subsequently setting the number of normal schedulers online back to 8 also sets the number of dirty CPU schedulers online back to 4. Augment the system_flag/2 documentation in the erlang man page to explain this relationship between schedulers_online and dirty_cpu_schedulers_online. Also ensure that all dirty CPU and I/O schedulers are suspended when multi-scheduling is blocked via system_flag/2, and brought back online when multi-scheduling is unblocked. Add Rickard Green's rewritten check_enqueue_in_prio_queue() function that inspects process state more thoroughly to determine if to enqueue it and if so on what queue, including dirty queues when appropriate. Make sure dirty NIF jobs do not trigger erlang:system_monitor long_schedule messages. Add more dirty scheduler testing to the scheduler test suite. Remove the erts_no_dirty_cpu_schedulers_online global variable, since it's no longer needed. Execute dirty NIFs on a normal scheduler thread while multi-scheduling blocking is in effect. Evacuate any dirty jobs residing in the dirty run queues over to a normal run queue when multi-scheduling is blocked. Allow dirty schedulers to execute aux work. Set the dirty run queues halt_in_progress flag when halting the normal schedulers. Change dirty scheduler numbers to a structure including both scheduler number and type, either dirty CPU or dirty I/O. Add some assertions to ensure that dirty CPU schedulers operate only on dirty CPU scheduler process flags, and the same for dirty I/O schedulers.
2014-01-09Fix issues with new versioningRickard Green
2013-08-29add erl option to set schedulers by percentagesSteve Vinoski
For applications where measurements show enhanced performance from the use of a non-default number of emulator scheduler threads, having to accurately set the right number of scheduler threads across multiple hosts each with different numbers of logical processors is difficult because the erl +S option requires absolute numbers of scheduler threads and scheduler threads online to be specified. To address this issue, add a +SP option to erl, similar to the existing +S option but allowing the number of scheduler threads and scheduler threads online to be set as percentages of logical processors configured and logical processors available, respectively. For example, "+SP 50:25" sets the number of scheduler threads to 50% of the logical processors configured, and the number of scheduler threads online to 25% of the logical processors available. The +SP option also interacts with any settings specified with the +S option, such that the combination of options "+S 4:4 +SP 50:50" (in either order) results in 2 scheduler threads and 2 scheduler threads online. Add documentation for the +SP option. Add tests for the +SP option to scheduler_SUITE. Add tests and documentation for two existing features of the +S option: +S 0:0 resets the scheduler thread count and scheduler threads online count to their defaults, and specifying negative numbers for +S results in those values being subtracted from the default values for the host.
2011-12-06Unlink test-proc instead of ensuring that it has died before stopping nodeRickard Green
Unlink the test-proc instead of monitoring it and waiting for it to terminate before stopping the node. This since an unlink is faster, simpler and in this case more stable.
2011-12-06Ensure test-proc is dead before stopping nodeRickard Green
2011-12-06Give slow machines more time to compute resultRickard Green
2011-09-21Increase timeout in scheduler_suspend for slow platformsLukas Larsson
2011-09-21Skip update_cpu_info if 'taskset' cannot be foundLukas Larsson
2011-02-23emulator tests: Eliminate some compiler warningsBjörn Gustavsson
2011-02-17Rename Suite Callback to Common Test HookLukas Larsson
2011-02-17Fix formatting for emulatorLukas Larsson
2011-02-17Add init_per_suite and end_per_suiteLukas Larsson
2011-02-17Add ts_install_scb to suite/0Lukas Larsson
2011-02-17Update emulator tests to conform with common_test standardLukas Larsson
2010-09-01Add testcase for erlang:system_info(update_cpu_info)Rickard Green
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.
2010-06-04Fix scheduler_suspend test when schedulers online isn't equal to the amount ↵Rickard Green
of schedulers
2010-01-22OTP-8386 Immediately repeated multi-scheduling block/unblock cycles usingRickard Green
erlang:system_flag(multi_scheduling, block | unblock) could deadlock the runtime system.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP