On Mon, Apr 29, 2019 at 02:52:50PM -0400, Steven Rostedt wrote:
> On Mon, 29 Apr 2019 11:06:58 -0700
> Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > +void replace_call(void *addr, const void *opcode, size_t len, void *target)
> > +{
> > + bp_int3_call_target = target;
> > + bp_int3_call_return = addr + len;
> > + bp_int3_handler_irqoff = emulate_call_irqoff;
> > + text_poke_bp(addr, opcode, len, emulate_call_irqon);
> > +}
>
> Note, the function tracer does not use text poke. It does it in batch
> mode. It can update over 40,000 calls in one go:
Note that Daniel is adding batch stuff to text_poke(), because
jump_label/static_key stuffs also end up wanting to change more than one
site at a time and IPI spraying the machine for every single instance is
hurting.
So ideally ftrace would start to use the 'normal' code when that
happens.
