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    SubjectRe: [PATCH] linux-2.5.43_vsyscall_A0
    This may be way out there, but has any consideration been
    given to high speed system calls. I have worked on systems
    where this was done for selected calls. Only selected state
    was saved. Only fast calls such as getpid, gettimeofday,
    etc. were allowed. The calls were still executed in system
    pages so there was still the context switch (i.e. the trap
    overhead) but very little state save/ restore. It used a
    different trap number so it did not impact the standard
    calls.

    You would need to defeat the standard way of checking if in
    the system so the standard system calls and interrupt code
    would think user space was executing. As I recall there was
    some mapping tricks played so that while not actually in the
    system map, it was still available.

    I had only a brief encounter with these calls so I may not
    have all the details right :(
    --
    George Anzinger george@mvista.com
    High-res-timers:
    http://sourceforge.net/projects/high-res-timers/
    Preemption patch:
    http://www.kernel.org/pub/linux/kernel/people/rml
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