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Date: Wed, 19 May 2010 14:51:39 -0700
From: Alfred Perlstein <alfred@freebsd.org>
To: Dan McNulty <dkmcnulty@gmail.com>
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Cc: freebsd-hackers@freebsd.org
Subject: Re: Efficient way to determine when a child process forks or calls
	exec
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* Dan McNulty <dkmcnulty@gmail.com> [100519 07:13] wrote:
> Thanks for all the great suggestions!
> 
> It looks like the kevent system call is the closest to what I need.
> However, I didn't mention this, but I would like the process being
> traced to be stopped on entrance to fork, exec, etc. This would be
> similar to Linux's ptrace interface which sends a SIGTRAP to the
> traced process on exec, fork, etc. From what I could tell so far,
> kevent doesn't provide this functionality.
> 
> Am I missing something? Is there a way to get kevent to stop the
> process when events occur?

Not that I know of off the top of my head.

Although if you want to contrib the code I can help get it in. :)

-Alfred


> 
> Thanks again for your help,
> -Dan
> 
> On Tue, May 18, 2010 at 2:40 AM, Alfred Perlstein <alfred@freebsd.org> wrote:
> > * Dan McNulty <dkmcnulty@gmail.com> [100517 08:02] wrote:
> >> Hi all,
> >>
> >> I have been experimenting with ptrace to determine when a child
> >> process forks or calls exec. Particularly, I have explored tracing
> >> every system call entry and exit similar to what the truss utility
> >> does, and for my case, the performance impact of tracing every system
> >> call is too great.
> >>
> >> Is there a more efficient way than tracing every system call entry and
> >> exit to determine when a child process forks, calls exec, or creates a
> >> new LWP?
> >>
> >> Thanks a lot for your help!
> >
> > kevent has some hooks, have you looked at that?
> >
> > --
> > - Alfred Perlstein
> > .- AMA, VMOA #5191, 03 vmax, 92 gs500, 85 ch250, 07 zx10
> > .- FreeBSD committer
> >

-- 
- Alfred Perlstein
.- AMA, VMOA #5191, 03 vmax, 92 gs500, 85 ch250, 07 zx10
.- FreeBSD committer