Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752351AbdLUIzb (ORCPT <rfc822;w@1wt.eu>);
        Thu, 21 Dec 2017 03:55:31 -0500
Received: from szxga06-in.huawei.com ([45.249.212.32]:52380 "EHLO huawei.com"
        rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP
        id S1752278AbdLUIza (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 21 Dec 2017 03:55:30 -0500
Message-ID: <5A3B76EE.8020001@huawei.com>
Date: Thu, 21 Dec 2017 16:55:10 +0800
From: Xishi Qiu <qiuxishi@huawei.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1
MIME-Version: 1.0
To: Toshi Kani <toshi.kani@hp.com>, "H. Peter Anvin" <hpa@zytor.com>,
        "Thomas Gleixner" <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>
CC: LKML <linux-kernel@vger.kernel.org>, Linux MM <linux-mm@kvack.org>,
        "Xishi Qiu" <qiuxishi@huawei.com>
Subject: [RFC] does ioremap() cause memory leak?
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.177.25.179]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 380
Lines: 9

When we use iounmap() to free the mapping, it calls unmap_vmap_area() to clear page table,
but do not free the memory of page table, right?

So when use ioremap() to mapping another area(incluce the area before), it may use
large mapping(e.g. ioremap_pmd_enabled()), so the original page table memory(e.g. pte memory)
will be lost, it cause memory leak, right?

Thanks,
Xishi Qiu