From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id EA1BF6B0069 for ; Thu, 13 Oct 2016 20:24:45 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id t25so94084941pfg.3 for ; Thu, 13 Oct 2016 17:24:45 -0700 (PDT) Received: from mail-pf0-x235.google.com (mail-pf0-x235.google.com. [2607:f8b0:400e:c00::235]) by mx.google.com with ESMTPS id z4si12920403pgb.66.2016.10.13.17.24.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 13 Oct 2016 17:24:45 -0700 (PDT) Received: by mail-pf0-x235.google.com with SMTP id 128so42026493pfz.0 for ; Thu, 13 Oct 2016 17:24:45 -0700 (PDT) Date: Thu, 13 Oct 2016 20:24:41 -0400 From: Tejun Heo 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> Sender: owner-linux-mm@kvack.org List-ID: To: zijun_hu Cc: zijun_hu@htc.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , cl@linux.com 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org