Re: aio is unlikely

From: Andrew Morton
Date: Fri May 18 2007 - 18:15:56 EST


On Fri, 18 May 2007 17:54:32 -0400
Phillip Susi <psusi@xxxxxxxxxx> wrote:

> Andrew Morton wrote:
> > Yes, if you agree with Jeff's original point.
> >
> > But I don't, actually. Sure, on some machines+workloads, AIO is more
> > common than sync IO. But I expect that when we sum across all the
> > machines+workloads in the world, sync IO is more common and is hence the
> > case we should optimise for.
> >
> > That's assuming that the unlikely() actually does something.
>
> But as Jeff said, that's not what unlikely is for. It should only be
> used when it is unlikely for everybody, all the time, because when it is
> right, it helps rather little, but when it is wrong, it hurts a lot.

It does? Tell us more.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/