Re: trace-cmd errors on kvm events

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, Apr 08, 2011 at 11:07:23PM +0200, Jan Kiszka wrote:
> On 2011-04-08 20:53, David Ahern wrote:
> > 2.6.38.2 kernel with trace-cmd git pulled this morning:
> > 
> > trace-cmd record -e kvm
> > 
> > trace-cmd report 2>&1 | less
> > 
> > trace-cmd: No such file or directory
> 
> Does this error come from trace-cmd failing to find its kvm plugin?
> Check what strace -e open says.
> 

I need to spend some time and fix it. That "No such file or directory"
is from the way trace-cmd does error handling. It checks if errno is set
and if so, it prints out perror(). What usually happens is I do a stat()
on a file which sets errno, and forget about it. Then if trace-cmd finds
some internal error, it calls the warning() message, which then prints
out the stale errno.

-- Steve