Subject: Re: linux-next: build warning after merge of the akpm-current tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 1 Aug 2019 15:51:30 +1000

Hi Miles,

On Wed, 31 Jul 2019 14:28:04 +0800 Miles Chen <[email-masked]> wrote:
>
> On Wed, 2019-07-31 at 16:11 +1000, Stephen Rothwell wrote:
> > 
> > After merging the akpm-current tree, today's linux-next build (powerpc
> > ppc64_defconfig) produced this warning:
> > 
> > mm/memcontrol.c: In function 'invalidate_reclaim_iterators':
> > mm/memcontrol.c:1160:11: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
> >   } while (memcg = parent_mem_cgroup(memcg));
> >            ^~~~~
> >   
> 
> Hi Stephen,
> 
> Thanks for the telling me this. Sorry for the build warning. 
> Should I send patch v5 to the mailing list to fix this? 

You might as well (cc'ing Andrew, of course).

I would suggest finishing that loop like this:

		memcg = parent_mem_cgroup(memcg);
	} while (memcg);

rather than adding a set of parentheses.

-- 
Cheers,
Stephen Rothwell