Sticky Bit - History

History

The sticky bit was introduced in the Fifth Edition of Unix for use with pure executable files. When set, it instructed the operating system to retain the text segment of the program in swap space after the process exited. This speeds up subsequent executions by allowing the kernel to make a single operation of moving the program from swap to real memory. Thus, frequently-used programs like editors would load noticeably faster. One notable problem with "stickied" programs was replacing the executable (for instance, during patching); to do so required removing the sticky bit from the executable, executing the program and exiting to flush the cache, replacing the binary executable, and then restoring the sticky bit.

Currently, this behavior is only operative in HP-UX, NetBSD, and UnixWare. Solaris appears to have abandoned this in 2005. The 4.4-Lite release of BSD retained the old sticky bit behavior but it has been subsequently dropped from OpenBSD (as of release 3.7) and FreeBSD (as of release 2.2.1); it remains in NetBSD. No version of Linux has ever supported this traditional behaviour.

Read more about this topic:  Sticky Bit

Famous quotes containing the word history:

    “The history of reform is always identical; it is the comparison of the idea with the fact. Our modes of living are not agreeable to our imagination. We suspect they are unworthy. We arraign our daily employments.”
    —Ralph Waldo Emerson (1803–1882)

    “What is most interesting and valuable in it, however, is not the materials for the history of Pontiac, or Braddock, or the Northwest, which it furnishes; not the annals of the country, but the natural facts, or perennials, which are ever without date. When out of history the truth shall be extracted, it will have shed its dates like withered leaves.”
    —Henry David Thoreau (1817–1862)

    “A people without history
    Is not redeemed from time, for history is a pattern
    Of timeless moments.”
    —T.S. (Thomas Stearns)