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    SubjectQuestion about setting affinity in 2.4
    Hello everyone,

    I am trying to set affinity on a program to make sure I can get the
    best use of the cache as possible and to eliminate as much noise as
    possible with running my program. I have tried unsuccessfully to set
    affinity using sched_set/getaffinity and the CPU_SET macros. In
    particular, I can not seem to get the process to use affinity I
    specify as in:

    int main () {
    cpu_set_t mask;
    cpu_set_t setmask;
    long long x;
    double foo;
    printf("Mask set to %08lx\n", sched_getaffinity(0, &mask));
    CPU_SET(1, &mask);
    if (sched_setaffinity(0, &mask) == -1) {
    printf("error setting affinity.");
    }

    printf("Mask is reset to %08lx\n", sched_getaffinity(0, &mask));
    // do some long lasting calculations ....

    return;
    }

    No mater what I do, the process is never bond to the processor in
    question as exposed by this little appy and by cat /proc/<pid>/cpu.
    Is this just impossible to do?

    Ah, the kernel I am using is RH 2.4.21-37.ELsmp.

    TIA!
    Phy
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