On Wed, 2009-09-16 at 00:39 -0400, Mike Frysinger wrote:
> On Tue, Sep 15, 2009 at 05:24,  <[email protected]> wrote:
> > Modified: trunk/arch/blackfin/kernel/ftrace-entry.S (7339 => 7340)
> >
> > @@ -21,6 +21,12 @@
> >   * will be waiting there.  mmmm pie.
> >   */
> >  ENTRY(__mcount)
> > +   /* __mcount is called this way:
> > +    * parent_ip: [--sp] = rets; call __mcount; rets = [sp++]
> > +    */
> > +   [--sp] = r1;
> > +   r1 = [sp + 4];
> > +
> >     /* save third function arg early so we can do testing below */
> >     [--sp] = r2;
> >
> > @@ -58,26 +64,24 @@
> >  #endif
> >
> >     r2 = [sp++];
> > +   r1 = [sp++]
> >     rts;
> >
> >  .Ldo_trace:
> >
> > -   /* save first/second function arg and the return register */
> >     [--sp] = r0;
> > -   [--sp] = r1;
> >     [--sp] = rets;
> 
> why did you need to move the r1 save/restore location ?  the early
> code doesnt need r1 and it's been specifically coded to avoid any
> unnecessary overhead in the most common case -- ftrace is completely
> disabled.
I did not take the overhead of "[--sp] = r1" into consideration. OK, I
will check in a new patch to fix this.
-Yi

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