Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 22 Jan 2018 07:55:59 -0800
From:   Tejun Heo <tj@kernel.org>
To:     Xiongwei Song <sxwjean@me.com>
Cc:     guro@fb.com, longman@redhat.com, davem@davemloft.net,
        akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        sxwjean@gmail.com
Subject: Re: [PATCH] cgroup: remove incorrect check on the return value of
 css_alloc
Message-ID: <20180122155559.GC1096857@devbig577.frc2.facebook.com>
References: <20180122133851.19772-1-sxwjean@me.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20180122133851.19772-1-sxwjean@me.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hello,

On Mon, Jan 22, 2018 at 09:38:51PM +0800, Xiongwei Song wrote:
> The function css_alloc never return NULL, it may return normal pointer or

It's a calling a controller implemented method.  I'd much rather keep
the extra protection.

> error codes that made by ERR_PTR, so !css is always false, we need use
> IS_ERR to check it, and if this is true, we should use ERR_CAST handle it.

It's of the same type.  Why would it need casting?

Thanks.

-- 
tejun