From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97C03C433ED for ; Thu, 1 Apr 2021 04:34:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 640C56023E for ; Thu, 1 Apr 2021 04:34:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230265AbhDAEe0 (ORCPT ); Thu, 1 Apr 2021 00:34:26 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:40707 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229473AbhDAEdp (ORCPT ); Thu, 1 Apr 2021 00:33:45 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4F9r0G3VJcz9sRf; Thu, 1 Apr 2021 15:33:17 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1617251598; bh=wRu7ThPbLuUkFDWwkgb0lsalLwoPfWRY58ouNkBsX0k=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=otEeA36Cj4+17EP9f4va3/Da3w2s4/MBh3E+sEeaAjmqK/wDQ2NKFiVj2YcnQyssI krtHRDfMK7qlU7lc5iwBxlq+/m1Lod9pwkzGfqsQg1+b/2I/3ndJSFANLyCYs7vwan dh/pbRIKTW65MyvCy5TFas6Rsj2eVCozF7K9xDZCcygyBODCoZH5dtR4tLiQhgiGi5 5lrULe3tjOuZqGSXHXxmZjl+pweunu5GHqj9nh48a7c0h7U90FB6aMj4nDWzv7eBQA krbqyZD15xzUAr0PGTjVa86Lf0K1TVGAJ7+cwKgMCb/7x3Z4DlztvbwN2SqgdZDQK5 SaOh6et7BcUUQ== From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Jordan Niethe Subject: Re: [PATCH] powerpc/8xx: Load modules closer to kernel text In-Reply-To: References: <87czvf788t.fsf@mpe.ellerman.id.au> Date: Thu, 01 Apr 2021 15:33:13 +1100 Message-ID: <87ft0a1v5i.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy writes: > Le 31/03/2021 =C3=A0 15:39, Michael Ellerman a =C3=A9crit=C2=A0: >> Christophe Leroy writes: >>> On the 8xx, TASK_SIZE is 0x80000000. The space between TASK_SIZE and >>> PAGE_OFFSET is not used. >>> >>> Use it to load modules in order to minimise the distance between >>> kernel text and modules and avoid trampolines in modules to access >>> kernel functions or other module functions. >>> >>> Define a 16Mbytes area for modules, that's more than enough. >>=20 >> 16MB seems kind of small. >>=20 >> At least on 64-bit we could potentially have hundreds of MBs of modules. >>=20 > > Well, with a 16 MB kernel and 16 MB modules, my board is full :) Heh. > Even on the more recent board that has 128 MB, I don't expect more than a= few MBs of modules in=20 > addition to the kernel which is approx 8M. > > But ok, I'll do something more generic, though it will conflict with Jord= an's series. Don't feel you have to. You're the expert on 8xx, not me. cheers