The highlight of this release is the reduction of lock contention for all I/O operations (#5300). We have received reports of up to a 20% improvement in CPU utilization and increased throughput for real-world I/O heavy applications.

Fixed

• rt: improve native AtomicU64 support detection (#5284)

Added

• rt: add configuration option for max number of I/O events polled from the OS
  per tick (#5186)
• rt: add an environment variable for configuring the default number of worker
  threads per runtime instance (#4250)

Changed

• sync: reduce MPSC channel stack usage (#5294)
• io: reduce lock contention in I/O operations (#5300)
• fs: speed up read_dir() by chunking operations (#5309)
• rt: use internal ThreadId implementation (#5329)
• test: don't auto-advance time when a spawn_blocking task is running (#5115)