From: "Devon H. O'Dell" <devon.odell@gmail.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: Re: [9fans] syscall spikes
Date: Tue, 17 Apr 2007 11:38:33 -0400 [thread overview]
Message-ID: <9ab217670704170838g363bba09pc0328e13106d0efd@mail.gmail.com> (raw)
In-Reply-To: <9ab217670704170822s6e9649f2u7694a994498d7c6b@mail.gmail.com>
2007/4/17, Devon H. O'Dell <devon.odell@gmail.com>:
> 2007/4/17, Uriel <uriel99@gmail.com>:
> > 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 <devon.odell@gmail.com> 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
> > >
> >
>
next prev parent reply other threads:[~2007-04-17 15:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-17 14:15 Devon H. O'Dell
2007-04-17 14:36 ` Uriel
2007-04-17 15:22 ` Devon H. O'Dell
2007-04-17 15:38 ` Devon H. O'Dell [this message]
2007-04-17 15:45 ` erik quanstrom
2007-04-17 15:56 ` Devon H. O'Dell
2007-04-17 16:29 ` Devon H. O'Dell
2007-04-17 16:39 ` Devon H. O'Dell
2007-04-17 15:49 ` Charles Forsyth
2007-04-18 16:53 ` Russ Cox
2007-04-18 16:59 ` Devon H. O'Dell
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