From owner-freebsd-current@FreeBSD.ORG  Sat Oct  4 15:58:08 2014
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id D8F726D5;
 Sat,  4 Oct 2014 15:58:08 +0000 (UTC)
Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 64F0B2D8;
 Sat,  4 Oct 2014 15:58:08 +0000 (UTC)
Received: from tom.home (kostik@localhost [127.0.0.1])
 by kib.kiev.ua (8.14.9/8.14.9) with ESMTP id s94Fw3mv034704
 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO);
 Sat, 4 Oct 2014 18:58:03 +0300 (EEST)
 (envelope-from kostikbel@gmail.com)
DKIM-Filter: OpenDKIM Filter v2.9.2 kib.kiev.ua s94Fw3mv034704
Received: (from kostik@localhost)
 by tom.home (8.14.9/8.14.9/Submit) id s94Fw3X3034703;
 Sat, 4 Oct 2014 18:58:03 +0300 (EEST)
 (envelope-from kostikbel@gmail.com)
X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com
 using -f
Date: Sat, 4 Oct 2014 18:58:03 +0300
From: Konstantin Belousov <kostikbel@gmail.com>
To: stable@freebsd.org, freebsd-current@freebsd.org
Subject: Re: About pmap_mapdev() & pmap_unmapdev()
Message-ID: <20141004155803.GQ26076@kib.kiev.ua>
References: <20141004082943.GN26076@kib.kiev.ua>
 <20141004.175326.766405563100788209.okuno.kohji@jp.panasonic.com>
 <20141004092030.GP26076@kib.kiev.ua>
 <20141004.205335.1782700760623869892.okuno.kohji@jp.panasonic.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20141004.205335.1782700760623869892.okuno.kohji@jp.panasonic.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00,
 DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no
 autolearn_force=no version=3.4.0
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on tom.home
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
 <freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-current>, 
 <mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current/>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
 <mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 04 Oct 2014 15:58:08 -0000

On Sat, Oct 04, 2014 at 08:53:35PM +0900, Kohji Okuno wrote:
> Hi Konstantin,
> 
> Thank you for your prompt response.
> I will test and report from next monday.
> 
> >> In addtion, I have one question.
> >> In current and 10-stable, is vm_map_delete() called by kva_free()?
> > No, kva_free() only releases the vmem backing, leaving the page
> > tables intact.  This is why I only did the stable/9 patch.
> 
> Where are PTEs allocated by pmap_mapdev() freed in current and 10-stable?
> Could you please explain me?
They are not freed. The removal of the vmem which covers the address
space managed by corresponding ptes, allows the reuse of both KVA region
and corresponding PTEs in the tables. The only concern with the resident
page tables is to avoid two kva_alloc() to step over each other, and
this is ensured by vmem.