From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752378AbdLSPDj (ORCPT <rfc822;w@1wt.eu>);
        Tue, 19 Dec 2017 10:03:39 -0500
Received: from verein.lst.de ([213.95.11.211]:38728 "EHLO newverein.lst.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752258AbdLSPDd (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 19 Dec 2017 10:03:33 -0500
Date: Tue, 19 Dec 2017 16:03:32 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, X86 ML <x86@kernel.org>,
        Linux MM <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 14/17] memremap: simplify duplicate region handling in
        devm_memremap_pages
Message-ID: <20171219150332.GB13124@lst.de>
References: <20171215140947.26075-1-hch@lst.de> <20171215140947.26075-15-hch@lst.de> <CAPcyv4i2naLJjWzm+q0ORRfyHkT0f5dFBFKutuaXE3OgPcHX5g@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CAPcyv4i2naLJjWzm+q0ORRfyHkT0f5dFBFKutuaXE3OgPcHX5g@mail.gmail.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sun, Dec 17, 2017 at 09:34:11AM -0800, Dan Williams wrote:
> This is not racy, we'll catch the error on insert, and I think the
> extra debug information is useful for debugging a broken memory map or
> alignment math.

We can check for -ЕEXIST and print the warning, but it's a weird pattern
for sure.