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

From: Michal Hocko
Date: Thu Aug 01 2019 - 02:15:41 EST


On Thu 01-08-19 15:51:30, Stephen Rothwell wrote:
> Hi Miles,
>
> On Wed, 31 Jul 2019 14:28:04 +0800 Miles Chen <miles.chen@xxxxxxxxxxxx> 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.

Qian has already posted a patch http://lkml.kernel.org/r/1564580753-17531-1-git-send-email-cai@xxxxxx
--
Michal Hocko
SUSE Labs