OTP_R15A: R15 pre-release
Written by Kenneth, 23 Nov 2011

We have recently pushed a new master to GitHub tagged OTP_R15A.

This is a stabilized snapshot of the current R15 development (to be released as R15B on December 14:th) which, among other things, includes:

OTP-9468  'Line numbers in exceptions'

OTP-9451  'Parallel make'

OTP-4779  A new GUI for Observer. Integrating pman, etop and tv into
                    observer with tracing facilities.

OTP-7775  A number of memory allocation optimizations have been
             implemented. Most optimizations reduce contention caused by
             synchronization between threads during allocation and
             deallocation of memory. Most notably:
             Synchronization of memory management in scheduler specific
             allocator instances has been rewritten to use lock-free

             Synchronization of memory management in scheduler specific
             pre-allocators has been rewritten to use lock-free

             The 'mseg_alloc' memory segment allocator now use scheduler
             specific instances instead of one instance. Apart from
             reducing contention this also ensures that memory allocators
             always create memory segments on the local NUMA node on a
             NUMA system.

OTP-9632  An ERTS internal, generic, many to one, lock-free queue for
             communication between threads has been introduced. The many
             to one scenario is very common in ERTS, so it can be used in
             a lot of places in the future. Currently it is used by
             scheduling of certain jobs, and the async thread pool, but
             more uses are planned for the future.

             Drivers using the driver_async functionality are not
             automatically locked to the system anymore, and can be
             unloaded as any dynamically linked in driver.

             Scheduling of ready async jobs is now also interleaved in
             between other jobs. Previously all ready async jobs were
             performed at once.

OTP-9631  The ERTS internal system block functionality has been
             replaced by new functionality for blocking the system. The
             old system block functionality had contention issues and
             complexity issues. The new functionality piggy-backs on
             thread progress tracking functionality needed by newly
             introduced lock-free synchronization in the runtime system.
             When the functionality for blocking the system isn't used,
             there is more or less no overhead at all. This since the
             functionality for tracking thread progress is there and
             needed anyway.

... and much much more.

This is not a full release of R15 but rather a pre-release. Feel free to try our R15A release and get back to us with your findings.

Your feedback is important to us and highly welcomed.


The OTP Team