Re: [PATCH] ext3_clear_inode(): avoid kfree(NULL)

[Steven Rostedt]

On Sat, 24 Jun 2006, Arjan van de Ven wrote:

>
> >
> > Because at that callsite, NULL is the common case.  We avoid a do-nothing
> > function call most of the time.  It's a nano-optimisation.
>
> but a function call is basically free, while an if () is not... even
> with unlikely()...
>
> sounds like a misoptimization to me.
>

How is a function call free when an if is not?  Especially if that
function does the exact same if?

The problem is that in these cases the pointer is NULL several thousands
of times for every time it is not NULL (if ever).  The non-NULL case is
where an error occurred or something very special.  So I don't see how
the if here is a problem?

-- Steve

-
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/