Date:   Wed, 24 Nov 2021 13:23:42 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     cgel.zte@gmail.com
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, chiminghao <chi.minghao@zte.com.cn>,
        Zeal Robot <zealci@zte.com.cn>
Subject: Re: [PATCH] mm: Use BUG_ON instead of if condition followed by BUG
Message-ID: <YZ483gwnwTysPt0G@casper.infradead.org>
References: <20211124030849.34998-1-chi.minghao@zte.com.cn>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20211124030849.34998-1-chi.minghao@zte.com.cn>
Precedence: bulk

On Wed, Nov 24, 2021 at 03:08:49AM +0000, cgel.zte@gmail.com wrote:
> From: chiminghao <chi.minghao@zte.com.cn>
> 
> Fix the following coccinelle report:
> ./mm/memory_hotplug.c:2210:2-5:
> WARNING  Use BUG_ON instead of if condition followed by BUG.

What coccinelle script is reporting this?

> -	if (try_remove_memory(start, size))
> -		BUG();
> +	BUG_ON(try_remove_memory(start, size));

I really, really, really do not like this.  For functions with
side-effects, this is bad style.  If it's a pure predicate, then
sure, but this is bad.