On Sat, Aug 31, 2019 at 01:32:02PM -0700, Joe Perches wrote:

On Sat, 2019-08-31 at 17:25 +0200, Pali Rohár wrote:

quoted

On Thursday 29 August 2019 10:50:39 Dmitry Torokhov wrote:

quoted

On Thu, Aug 29, 2019 at 07:50:23PM +0300, Denis Efremov wrote:

quoted

"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.

The keyword here is _internally_.

https://lore.kernel.org/lkml/20190821174857.GD76194@dtor-ws/ (local)

So please no.

I think it poor form not to simply restate your original
objection from 4 message levels below this link

Thank you for the lesson in etiquette, but I posted reference to the
very message I wanted.

https://lists.gt.net/linux/kernel/2269724

   Hm... I do not like this change. If I read code 
    
    if (unlikely(IS_ERR_OR_NULL(priv->dev3))) 
    
   then I know that it is really unlikely that condition will be truth and 
   so this is some case of error/exception or something that normally does 
   not happen too much. 
    
   But if I read code 
    
    if (IS_ERR_OR_NULL(priv->dev3)) 
    
   I know nothing about chance that this condition will be truth. Explicit 
   unlikely in previous example give me more information. 
    
I alslo think this argument is dubious as it also applies
to any IS_ERR and all the unlikely uses have been removed
from those.

No, if you read the reference I posted, the argument does not apply to
all IS_ERR() instances. Majority of them are in probe() paths where we
do not really care about likely/unlikely. Here we are dealing with
IS_ERR in a [fairly] hot path.

Thanks.

-- 
Dmitry