Why is intr taking up so much cpu?
dougb at FreeBSD.org
Tue Jul 20 01:03:25 UTC 2010
I added options KDTRACE_HOOKS to my kernel config, built a new kernel,
and rebooted. I decided to try your script before things went sideways
so I'd have an idea of what to expect, and it didn't work:
dtrace: failed to initialize dtrace: DTrace device not available on
Is there something else I need to do to enable it?
On Sun, 18 Jul 2010, Dan Nelson wrote:
> You can also use dtrace to get a count of callouts and their time spent.
> Run this for a few seconds then hit ^C:
> #! /usr/sbin/dtrace -s
> /* #pragma D option quiet */
> this->start = timestamp;
> this->end = timestamp;
> /* printf("%a %d\n",args->c_func, this->end - this->start); */
> @times[args->c_func] = quantize(this->end - this->start);
> /* @times[args->c_func] = lquantize(this->end - this->start,0,300000,10000); */
> @counts[args->c_func] = count();
> printa("%a %@u\n", at times);
> printa("%a %@u\n", at counts);
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