FreeBSD Improvements to 4.4BSD-Lite

• VM system improvements
  • Improved page replacement algorithm.
  • Clustered page-ins and page-outs reduces disk seeks.
  • Direct paging I/O (not via buffer cache) improves performance.
  • ``Pre-faulting'' - map resident pages at mmap time eliminates initial paging overhead.
• I/O system improvements
  • Improved file I/O clustering algorithms, delayed writes are now clustered.
  • Bounce buffers allows using ISA DMA controllers with >16MB.
  • A merged VM/buffer cache uses all free memory for file caching and eliminates cache coherency problems.
• Network system improvements
  • Socket and TCP performance improved via greater use of mbuf clusters.
  • Connection hashing to improve speed of packet reception.
  • New multicast code from LBL.
  • Firewall capability with packet filtering and enhanced security auditing.
  • Support for high speed networking such as 100BT and FDDI.
• Miscellaneous improvements
  • SCO, Linux and System V emulation.
  • PCI support and PCMCIA support in --current.
  • Advanced Power Management for laptops.
  • Automatic loadable kernel modules.
  • Sun style shared libraries.
• Work in progress
  • Symmetric Multi-Processing.
  • Support for additional architectures: Sparc, PowerPC, ALPHA.
  • DOS emulation.
  • Additional VM system improvements.
  • Ext2FS filesystem and more advanced Linux emulation.