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Date:   Mon, 8 Jul 2019 10:31:37 -0700
From:   Tejun Heo <tj@kernel.org>
To:     Roman Gushchin <guro@fb.com>
Cc:     Peng Wang <rocking@whu.edu.cn>,
        "lizefan@huawei.com" <lizefan@huawei.com>,
        "hannes@cmpxchg.org" <hannes@cmpxchg.org>,
        "cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] cgroup: minor tweak for logic to get cgroup css
Message-ID: <20190708173137.GH657710@devbig004.ftw2.facebook.com>
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 <20190708164243.GE657710@devbig004.ftw2.facebook.com>
 <20190708172944.GA24662@tower.DHCP.thefacebook.com>
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On Mon, Jul 08, 2019 at 05:29:49PM +0000, Roman Gushchin wrote:
> On Mon, Jul 08, 2019 at 09:42:43AM -0700, Tejun Heo wrote:
> > On Wed, Jul 03, 2019 at 10:07:49AM +0800, Peng Wang wrote:
> > > We could only handle the case that css exists
> > > and css_try_get_online() fails.
> > 
> > As css_tryget_online() can't handle NULL input, this is a bug fix.
> > Can you please clarify that in the description?
> 
> -       if (!css || !css_tryget_online(css))
> +       if (css && !css_tryget_online(css))
> 
> If css == NULL, !css is true, and the second part of the || statement
> will not be evaluated. So it's not a bug fix.

Ah right, it's just confusing.  Will apply after the merge window.

Thanks.

-- 
tejun