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Re: Instrumenting context switches
On Wed, 2006-11-29 at 18:25 -0500, Perry Cheng wrote:
> probe kernel.function("__switch_to")
> {
> doSwitchTo(gettimeofday_us(), $prev_p, $next_p);
> }
>
> function doSwitchTo(timeus:long, prev:long, next:long)
> %{
> _stp_printf("SWITCHCOUNT = %ld\n", switchCount);
> <------------------------------ BAD LINE
> switchCount++;
> }%
Obviously the code fragment above is not exactly what you are using to
reproduce the bug. (You can't use keywords as parameter names,
uninitialized switchCount, "}%", etc). I tried the following and did
not see any problems. Can you give more details (arch, OS, etc) on how
to reproduce?
%{
long switchCount = 1000000;
%}
function doSwitchTo (t:long, p:long, n:long) %{
_stp_printf("SWITCHCOUNT = %ld\n", switchCount);
switchCount++;
%}
probe kernel.function("__switch_to")
{
doSwitchTo(gettimeofday_us(), $prev_p, $next_p);
}