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

[Linus Torvalds]

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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/