Messages in this thread | | | Date | Thu, 23 Feb 2012 18:18:42 -0500 | From | Mathieu Desnoyers <> | Subject | Re: [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs |
| |
* Ingo Molnar (mingo@elte.hu) wrote: > > * Ingo Molnar <mingo@elte.hu> wrote: > > > So, a modified scheme would be: > > > > #include <linux/static_key.h> > > > > struct static_key key = STATIC_KEY_INIT_TRUE; > > > > if (static_key_false(&key)) > > do unlikely code > > else > > do likely code > > > > Or: > > > > if (static_key_true(&key)) > > do likely code > > else > > do unlikely code > > > > The static key is modified via: > > > > static_key_slow_inc(&key); > > ... > > static_key_slow_dec(&key); > > > > Is that API fine? I'll rework the series to such an effect if > > everyone agrees. > > I.e. something like the patch below on top of > tip:perf/jump-labels. > > Untested - will test it and will refactor the series if > everyone's happy.
Hi Ingo,
Reading your documentation updates makes me realise that adding the "inline" keyword in there would make the whole thing even clearer:
struct static_key key = STATIC_KEY_INLINE_TRUE_INIT; struct static_key key = STATIC_KEY_INLINE_FALSE_INIT;
static_key_inline_true() / static_key_inline_false()
to show that the "true/false" in there does not mean that the key will always be true or false (the key value can indeed by changed by calling static_key_slow_inc/dec), but that the inlined path is either the true of false branch.
The rest looks fine.
Best regards,
Mathieu
-- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com
| |