Re: [PATCH 7/9] tracing: MIPS: Reduce the overhead of dynamic Function Tracer

[David Daney <david.s.daney@gmail.com>]

On 05/14/2010 07:43 PM, Wu Zhangjin wrote:
> On Fri, 2010-05-14 at 10:15 -0700, David Daney wrote:
>    
> > On 05/14/2010 04:08 AM, Wu Zhangjin wrote:
> >      
> > > From: Wu Zhangjin<wuzhangjin@gmail.com>
> > >
> > > With the help of uasm, this patch encodes the instructions of dynamic
> > > Function Tracer in ftrace_dyn_arch_init() when initializing it.
> > >
> > >        
> > [...]
> >      
> > > +#include<asm/uasm.h>
> > >
> > >        
> > All of uasm is _cpuinit, I haven't checked everything, but are you sure
> > you aren't calling if from non-_cpuinit code?
> >      
> The calling tree looks like this:
>
> start_kernel()  // __init
>    -->  ftrace_init()  // __init
>          -->  ftrace_dyn_arch_init() // __init
>                -->  ftrace_dyn_arch_init_insns() // inline
>                     -->  uasm_*/UASM_*
>
> Nobody else will call uasm_*/UASM_* in this patch, I have checked the
> uasm usage in arch/mips/kernel/traps.c. Seems the usam functions are
> also called in the __init *set_except_vector(). so, it will also be safe
> in this patch, is it?
>
>    
Yes, that seems good to me.  I just wanted to make sure that this wasn't 
being called from non-init code.
David Daney