From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264776AbUEETvm (ORCPT ); Wed, 5 May 2004 15:51:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264775AbUEETvm (ORCPT ); Wed, 5 May 2004 15:51:42 -0400 Received: from mx1.redhat.com ([66.187.233.31]:28083 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S264776AbUEETvh (ORCPT ); Wed, 5 May 2004 15:51:37 -0400 Subject: Re: 2.6.6-rc3-mm2 (4KSTACK) From: Arjan van de Ven Reply-To: arjanv@redhat.com To: Steve Lord Cc: Andrew Morton , Dominik Karall , linux-kernel@vger.kernel.org In-Reply-To: <40991A8D.5000008@xfs.org> References: <20040505013135.7689e38d.akpm@osdl.org> <200405051312.30626.dominik.karall@gmx.net> <20040505043002.2f787285.akpm@osdl.org> <40991A8D.5000008@xfs.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-GN8LQbSjHp99QiHkw6N4" Organization: Red Hat UK Message-Id: <1083786663.3844.10.camel@laptop.fenrus.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Wed, 05 May 2004 21:51:03 +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-GN8LQbSjHp99QiHkw6N4 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > Is it less pain than making something like a memory allocation which come= s > out of a deep stack? Say, nfs server -> filesystem -> lvm/raid -> fiber c= hannel, > which itself does something like a writepage into an nfs filesystem and e= nds > up in the networking stack? OK, getting back into the filesystem on a > memory allocation from the block layer should not happen, but you could > certainly be down in it's not really much different than the 2.4 kernel already has. In 2.4 you have a 8Kb stack of which First 1600 bytes (+/-) are for the task struct about 4Kb of user context stack >=3D 2Kb stack which is needed for irq context (both soft and hard) In 2.6 with this patch you have 32 bytes for thread info 4Kb minus 32 bytes for context stack SEPARATE softirq stack of 4K SEPARATE hardirq stack of 4K so in a way you have MORE stack space than in 2.4. Now I'll fully admit the 2Kb is somewhat of a stochast, you only hit it if you have iptable rules and 2 nic irq's arriving on the same cpu at an unfortionate moment, but that doesn't mean it's a safe situation. --=-GN8LQbSjHp99QiHkw6N4 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQBAmUWnxULwo51rQBIRArsFAJ4vH/Evmq46bzVJscXHfGpmMiD+IwCcD8Ap 8NjHc6qyf9nJaC6GejmbbJA= =MRTu -----END PGP SIGNATURE----- --=-GN8LQbSjHp99QiHkw6N4--