Linux kernel 3.5 brings various interesting features (check out the highlights below and the quote from Linus Torvalds??? announcement) among which we can mention support for metadata checksums in the EXT4 filesystem, support for restoring and checkpointing TCP connections, support for TCP Early Retransmit (RFC 5827), a new network queue management algorithm designed to fight bufferbloat, Btrfs I/O failure statistics, and much more.