Subject: Re: typed copyin/copyout (was: Re: Show sysctl activity in ktrace)
To: Jason Thorpe <>
From: David Laight <>
List: tech-kern
Date: 09/21/2006 07:50:23
On Wed, Sep 20, 2006 at 11:36:48PM -0700, Jason Thorpe wrote:
> If we really want a better ktrace, we should get rid of it completely  
> and instead integrate dtrace from OpenSolaris.

Certainly something that works the way the SVR4 (and probably solaris)
'truss' program does [1] would be better for general monitoring of
programs - rather than splatting printf calls throughout the kernel.
Of course you lose the tracing of internal kernel events - eg namei.


[1] process blocks on syscall entry/exit allowing the tracing process
to determine the syscall arguments and read (write??) the traced
processes memory.  truss is just a very large nested switch statement
with lots of printf call - but they are all in userspace.

David Laight: