Re: [PATCH 3/4] SUNRPC: Replace dprintk() call site in xs_data_ready

[Steven Rostedt]

[ Added the user space perf folks ]

On Fri, 22 Jul 2022 18:45:30 +0000
Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote:

> >> +TRACE_EVENT(xs_data_ready,
> >> +  TP_PROTO(
> >> +  const struct rpc_xprt *xprt
> >> +  ),
> >> +
> >> +  TP_ARGS(xprt),
> >> +
> >> +  TP_STRUCT__entry(
> >> +  __sockaddr(addr, xprt->addrlen)
> >> +  ),
> >> +
> >> +  TP_fast_assign(
> >> +  __assign_sockaddr(addr, &xprt->addr, xprt->addrlen);
> >> +  ),
> >> +
> >> +  TP_printk("peer=%pISpc", __get_sockaddr(addr))  
> > 
> > NACK. Please resolve and store the string up front instead of storing
> > the sockaddr. Most versions of perf can't resolve those kernel-specific
> > %p printks and just end up barfing on them.  
> 
> Interesting. We added get_sockaddr() to avoid this issue in
> trace-cmd. Sounds like perf needs to be fixed up too, or
> maybe this is another case of having an old libtraceevent?
> 
> Meanwhile, I can revert this back to the old way of handling
> presentation addresses.
> 

Hmm, I thought that perf now uses the external libtraceevent.

Perhaps it hasn't been updated to the latest release that has the ability
to parse this.

Maybe just install

  git://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git

?

-- Steve