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    SubjectRe: [PATCH] Make modules work in Linus' tree on ARM

    On 14 Aug 2003, Alan Cox wrote:
    >
    > And why can't you put the pointer size at the start of the buffer ?

    Historical aside: this was pretty much _exactly_ the bug that we used to
    have in the old style timer tick profiler: it was impossible to figure out
    what the "profile shift" value was. So you got a series of "unsigned int"
    counts, but you didn't know what the granularity was for the hit counting.

    That was fixed by just making read_profile() return the sample step size
    as the first word. See

    fs/proc/proc_misc.c: read_profile()

    and note the small

    while (p < sizeof(unsigned int) && count > 0) {
    put_user(*((char *)(&sample_step)+p),buf);
    buf++; p++; count--; read++;
    }

    loop (and a few "+1" things for adjusting size comparisons).

    Linus

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