Re: SCO: "thread creation is about a thousand times faster than on

From: Jesse Pollard (pollard@tomcat.admin.navo.hpc.mil)
Date: Tue Aug 29 2000 - 08:33:22 EDT

  • Next message: Richard B. Johnson: "Re: newbie question: tcp/ip in kernel"

    --------- Received message begins Here ---------

    >
    > On Mon, Aug 28, 2000 at 06:52:18PM -0400, Alexander Viro wrote:
    > >
    > >
    > > On Sun, 27 Aug 2000 yodaiken@fsmlabs.com wrote:
    > >
    > > > Again, it's a possible, but pointless feature. You want fork/exec
    > > > in the presence of a file system and memory protection. But since
    > >
    > > Funny. I didn't know that -11/20 had memory protection...
    >
    > PDP-11 had good memory protection. I think PDP 8 may even have had it.
    > None of this newfangled paging b.s. though.

    Yes and no. It depends on which system you had. If memory serves:

    11/05 - no
    11/10 - no
    11/20 - optional (not usally provided)
    11/30 - optional (depended on configuration)
    11/35 - included (may have been optional)
    11/40 - included (may have been optional)
    11/45 - included (all versions higher than 45 included MM built in)

    Then there are the LSI versions:

    LSI 11 - no
    LSI 11/34 and higher - yes (11/34M equivalent - the M was memory management)

    In the PDP-11/45 (the first version to have MM) memory management was an
    add-on capability and was available without.

    Many of these systems were used in embeded configurations. The PDP-10 used
    an 11/20 as an IO/communications controller, and had an optional mm unit
    to be able to address the 18bit range of the PDP-10 (and DecSystem 10).
    It was optional because the PDP-10 didn't always have the memory that would
    demand it.

    The 11/30 was used in some aircraft equipment.

    The 11/40 was used where the embeded system needed floating point. I think
    that was in custom autopilots (not seen often).

    -------------------------------------------------------------------------
    Jesse I Pollard, II
    Email: pollard@navo.hpc.mil

    Any opinions expressed are solely my own.
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    Please read the FAQ at http://www.tux.org/lkml/



    This archive was generated by hypermail 2b29 : Tue Aug 29 2000 - 08:34:25 EDT