From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <9ab217670704170838g363bba09pc0328e13106d0efd@mail.gmail.com> Date: Tue, 17 Apr 2007 11:38:33 -0400 From: "Devon H. O'Dell" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] syscall spikes In-Reply-To: <9ab217670704170822s6e9649f2u7694a994498d7c6b@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <9ab217670704170715i1e62ed48k9817177886add100@mail.gmail.com> <5d375e920704170736h1fe36545oc2a95e082fe8e4c9@mail.gmail.com> <9ab217670704170822s6e9649f2u7694a994498d7c6b@mail.gmail.com> Topicbox-Message-UUID: 4b0316b6-ead2-11e9-9d60-3106f5b1d025 2007/4/17, Devon H. O'Dell : > 2007/4/17, Uriel : > > fossil > > I attempted to tprof fossil and I don't get any useful output. I even did: > > for (i in `{ps a | grep fossil | awk '{ print $2 }'}) > echo profile > /proc/$i/ctl > > [wait a while for spike] > > for (i in `{ps a | grep fossil | awk '{ print $2 }'}) { > echo $i > tprof $i > } > > All I get is a bunch of lines saying ``total: 0''. > > What'm I missing? :( I found the [undocumented] startsyscall argument to the process ctl file, but I cannot get it to work. If I echo startsyscall > /proc/N/ctl, I get ``echo: write error: bad process or channel control request''. What gives? --dho > --dho > > > On 4/17/07, Devon H. O'Dell wrote: > > > Hi, > > > > > > I've been having syscall spikes. It's really weird. There will be > > > >40,000 in 1 second, (according to stats(8)) and it appears at a > > > fairly regular interval. I've tried running kprof, but I'm not sure > > > that it's running a global profile. Namely, when I come out of it, I > > > have tons of time spent in ``halt'', with very, very few (<100) > > > syscalls. Any ideas what I can do to find the culprit? It's gapping > > > sound playback, which is really annoying. > > > > > > --dho > > > > > >