Date: Mon, 19 Jul 2010 18:03:21 -0700 (PDT) From: Doug Barton <dougb@FreeBSD.org> To: Dan Nelson <dnelson@allantgroup.com> Cc: Kostik Belousov <kostikbel@gmail.com>, freebsd-current@freebsd.org, Rui Paulo <rpaulo@freebsd.org> Subject: Re: Why is intr taking up so much cpu? Message-ID: <alpine.BSF.2.00.1007191800460.1873@qbhto.arg> In-Reply-To: <20100718202338.GI5485@dan.emsphone.com> References: <A81B337F-5932-44B1-BDB4-D9DD36332A16@lavabit.com> <alpine.BSF.2.00.1007171103060.1546@qbhto.arg> <F653FF83-D9CF-42A2-AE9A-B8F914090065@FreeBSD.org> <alpine.BSF.2.00.1007171208010.1538@qbhto.arg> <20100717192128.GM2381@deviant.kiev.zoral.com.ua> <alpine.BSF.2.00.1007180113370.1707@qbhto.arg> <20100718103003.GO2381@deviant.kiev.zoral.com.ua> <4C43541C.3060101@FreeBSD.org> <20100718194109.GU2381@deviant.kiev.zoral.com.ua> <4C435CBE.50500@FreeBSD.org> <20100718202338.GI5485@dan.emsphone.com>
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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
system
Is there something else I need to do to enable it?
Doug
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 */
>
> callout_execute:::callout_start
> {
> this->start = timestamp;
> }
>
> callout_execute:::callout_end
> {
> this->end = timestamp;
> /* printf("%a %d\n",args[0]->c_func, this->end - this->start); */
> @times[args[0]->c_func] = quantize(this->end - this->start);
> /* @times[args[0]->c_func] = lquantize(this->end - this->start,0,300000,10000); */
> @counts[args[0]->c_func] = count();
> }
>
> END
> {
> printa("%a %@u\n",@times);
> printa("%a %@u\n",@counts);
> }
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