Date: Thu, 13 Oct 2016 20:24:41 -0400
From: Tejun Heo <tj@kernel.org>
To: zijun_hu <zijun_hu@zoho.com>
Cc: zijun_hu@htc.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>, cl@linux.com
Subject: Re: [RFC v2 PATCH] mm/percpu.c: fix panic triggered by BUG_ON()
 falsely
Message-ID: <20161014002441.GG32534@mtj.duckdns.org>
References: <57FCF07C.2020103@zoho.com>
 <20161013232902.GD32534@mtj.duckdns.org>
 <92d3e474-856a-7f78-a9c3-b83e5913cd13@zoho.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <92d3e474-856a-7f78-a9c3-b83e5913cd13@zoho.com>
User-Agent: Mutt/1.7.0 (2016-08-17)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 543
Lines: 18

Hello,

On Fri, Oct 14, 2016 at 08:06:10AM +0800, zijun_hu wrote:
> > I really can't decode what the actual issue is here.  Can you please
> > give an example of a concrete case?
> > 
> the right relationship between the number of CPUs @nr_cpus within a percpu group
> and the number of unites @nr_units within the same group is that
> @nr_units == roundup(@nr_cpus, @upa);

My question was whether there can be actual hardware configurations
where this code can fail and if so what they look like and how they
would fail.

Thanks.

-- 
tejun