DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=tvFYEcBw1eCD8M7bydTnqhN/tCxiw8jEZSzYlmnIGdh3tsk5ENGz5
	GPWXn6UJOHdTDfI0syJWc/6w50A48K+O5BpN45Mr6VFMyjbH5/D7EJSm12H9X+6a
	K6rtF8h3U2Y4nHicMVQXRM2LeDW+IkNXUl8lV8dzItWMjIgrlbJYBs=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Date: Wed, 20 Apr 2016 12:54:06 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Process map and fork problems
Message-ID: <20160420105406.GC26118@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <loom DOT 20160420T121651-786 AT post DOT gmane DOT org> <20160420104633 DOT GA26118 AT calimero DOT vinschen DOT de>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;	protocol="application/pgp-signature"; boundary="w7PDEPdKQumQfZlR"
Content-Disposition: inline
In-Reply-To: <20160420104633.GA26118@calimero.vinschen.de>
User-Agent: Mutt/1.5.24 (2015-08-30)

--w7PDEPdKQumQfZlR
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Apr 20 12:46, Corinna Vinschen wrote:
> Hi Achim,
>=20
> On Apr 20 10:27, Achim Gratz wrote:
> > I'm chasing a problem on some 32bit Windows installs that supposedly
> > happened after one of the Windows updates (and probably other software
> > updates) in the last few months (the affected users were unable to pin =
it
> > down further unfortunately).  It's obviously caused by two heap section=
s in
> > the process map that are smack dab in the middle of the address range u=
sed
> > by rebase:
> >=20
> > 20000000-200A0000 rw-p 00000000 0000:0000 0                   [heap]
> > 200A0000-38000000 =3D=3D=3Dp 000A0000 0000:0000 0                   [he=
ap]
>=20
> This is one heap.  The first region is just the already committed
> part, the remainder is the reserved part.
>=20
> THis is the standard Cygwin heap area on 32 bit machines, which always
> starts at 0x20000000.
>=20
> > These do not exist on 32bit Cygwin installs on 64bit Windows installati=
ons,
>=20
> On 64 bit systems, 32 bit applications have a 4 Gig virtual address
> space.  On 32 bit systems, procecces only have a 2 Gig virtual address
> space, unless the /3gb kernel option is given.
>=20
> On 64 bit systems and on /3gb enabled 32 bit systems, the heap of 32 bit
> Cygwin processes always starts at 0x80000000L.
>=20
> Since that isn't available on 32 bit systems by default, the heap has
> to start within the lower 2 Gigs.  That's where the 0x2000000 address
> comes from.
>=20
> If you have collisions because you're providing too many Cygwin DLLs,
> you have to tweak these installations manually.

We could also move the heap address for default 32 bit systems to
0x30000000 or 0x40000000 or whatever is more convenient.  However, every
memory area has its own problems in the tight 32 bit address space.
We shouldn't do this without more testing.

Alternatively, kick out the 32 bit systems ;)


Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--w7PDEPdKQumQfZlR
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=jziJ
-----END PGP SIGNATURE-----

--w7PDEPdKQumQfZlR--