Re: [PATCH 2/2] tracing: Document HAVE_FTRACE_SYSCALLS needs

[Frederic Weisbecker <fweisbec@gmail.com>]

On Sat, Sep 19, 2009 at 09:17:12AM +0200, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> 
> > Document the arch needed requirements to get the support for syscalls
> > tracing.
> > 
> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> > Cc: Ingo Molnar <mingo@elte.hu>
> > Cc: Steven Rostedt <rostedt@goodmis.org>
> > Cc: Li Zefan <lizf@cn.fujitsu.com>
> > Cc: Masami Hiramatsu <mhiramat@redhat.com>
> > Cc: Jason Baron <jbaron@redhat.com>
> > Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
> > Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> > Cc: Paul Mundt <lethal@linux-sh.org>
> > ---
> >  Documentation/trace/ftrace-design.txt |   11 ++++++++++-
> >  1 files changed, 10 insertions(+), 1 deletions(-)
> > 
> > diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
> > index 7003e10..04ab61c 100644
> > --- a/Documentation/trace/ftrace-design.txt
> > +++ b/Documentation/trace/ftrace-design.txt
> > @@ -216,7 +216,16 @@ If you can't trace NMI functions, then skip this option.
> >  HAVE_FTRACE_SYSCALLS
> >  ---------------------
> >  
> > -<details to be filled>
> > +You need very few things to get the syscalls tracing in an arch.
> > +
> > +- Have a NR_syscalls variable in <asm/unistd.h> that provides the number
> > +  of syscalls supported by the arch.
> > +- Implement arch_syscall_addr() that resolves a syscall address from a
> > +  syscall number.
> > +- Support the TIF_SYSCALL_TRACEPOINT thread flags
> > +- Put the trace_sys_enter() and trace_sys_exit() tracepoints calls from ptrace
> > +  in the ptrace syscalls tracing path.
> > +- Tag this arch as HAVE_FTRACE_SYSCALLS.
> 
> HAVE_FTRACE_SYSCALLS is not actually used anywhere.
> 
> 	Ingo


Ah, that has been renamed HAVE_SYSCALL_TRACEPOINTS recently.
What do you prefer? A delta patch or a rebase?

Thanks.