Re: [PATCH v3 09/11] Input: alps - remove unlikely() from IS_ERR*() condition
From: Joe Perches <joe@perches.com>
Date: 2019-08-31 20:32:07
Also in:
lkml
From: Joe Perches <joe@perches.com>
Date: 2019-08-31 20:32:07
Also in:
lkml
On Sat, 2019-08-31 at 17:25 +0200, Pali Rohár wrote:
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 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.