Date: Tue, 20 Jul 2010 11:46:00 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Doug Barton <dougb@freebsd.org> 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: <20100720164600.GA85770@dan.emsphone.com> In-Reply-To: <alpine.BSF.2.00.1007192259170.1725@qbhto.arg> References: <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> <alpine.BSF.2.00.1007192259170.1725@qbhto.arg>
next in thread | previous in thread | raw e-mail | index | archive | help
In the last episode (Jul 19), Doug Barton said: > 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: > > Okey dokey, here you go: > > http://people.freebsd.org/~dougb/normal-dtrace.txt > http://people.freebsd.org/~dougb/bad-dtrace.txt I don't see any real difference between those two runs, so maybe it's not a callout eating your CPU. How about running this for a few seconds, which will print all the stack traces seen during the sampling period: dtrace -n 'profile:::profile-276hz { @pc[stack()]=count(); }' On an otherwise idle system, you should see most of the counts in cpu_idle, with the remainder clustered in whatever code is eating your CPU. -- Dan Nelson dnelson@allantgroup.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100720164600.GA85770>