On Thu, Jun 19, 2014 at 09:25:36AM -0400, Tejun Heo wrote: > On Thu, Jun 19, 2014 at 12:02:29PM +0200, Rasmus Villemoes wrote: > > This change shaves a few bytes off the generated code. > > > > Signed-off-by: Rasmus Villemoes <[email protected]> > > --- > > mm/percpu.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/mm/percpu.c b/mm/percpu.c > > index 2ddf9a9..978097f 100644 > > --- a/mm/percpu.c > > +++ b/mm/percpu.c > > @@ -720,8 +720,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t > > align, bool reserved) > > if (unlikely(align < 2)) > > align = 2; > > > > - if (unlikely(size & 1)) > > - size++; > > + size += size & 1; > > I'm not gonna apply this. This isn't that hot a path. It's not > worthwhile to micro optimize code like this.
Another thing is that it isn't even clear whether the micro optimization is even actually better given that predicted branches are extremely cheap and this one is extremely predictable. So, again, let's please leave it to the compiler. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
