KernelTrap: vmsplice() versus COW

“While explaining the new splice() and tee() buffer management
system calls, Linus Torvalds made reference to some possible future
extensions. This included vmsplice(), a system call since
implemented by Jens Axboe ‘to basically do a ‘write to the buffer’,
but using the reference counting and VM traversal to actually fill
the buffer.’ Reviewing the implications of using such a system call
lead to a comparison with FreeBSD’s ZERO_COPY_SOCKET which uses COW
(copy on write)…”

Complete Story

Related Story:
Morton: Linux 2.6.14-mm2
(Nov 11, 2005)