Re: [RFC][PATCH 2/2] tracing/x86: basic implementation of syscall tracing for x86-64

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

* Ingo Molnar (mingo@elte.hu) wrote:
> 
> * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> 
> > * Frederic Weisbecker (fweisbec@gmail.com) wrote:
> >
> > > Provide the ptrace hooks and arch specific syscall numbers 
> > > to ftrace arch indepedant syscall numbers. For now it only 
> > > supports 4 syscalls to provide an example.
> > > 
> > 
> > Hi Frederic,
> > 
> > I already have the equivalent TIF_KERNEL_TRACE flag in my 
> > LTTng tree added to every Linux architecture. You might want 
> > to re-use this work rather than re-doing this. I don't mind 
> > changing the flag name.
> 
> Yeah. Note that the TIF bits are just one part - there are other 
> bits needed for HAVE_FTRACE_SYSCALLS arch support.
> 
> Also, i'd eventually expect the TIF bits to be converted to a 
> tracehook callback, not spread it to other architectures.
> 

The nice part about the TIF bit is that it permits adding this syscall
tracing feature without increasing the size of the thread_info struct
nor adding any extra tests in entry.S. Does the tracehook callback have
these features ?

Mathieu

> 	Ingo

-- 
Mathieu Desnoyers
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