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 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 6DDCCC4363E for ; Wed, 31 Mar 2021 13:39:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E8DA61981 for ; Wed, 31 Mar 2021 13:39:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236028AbhCaNjs (ORCPT ); Wed, 31 Mar 2021 09:39:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235928AbhCaNjS (ORCPT ); Wed, 31 Mar 2021 09:39:18 -0400 Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 608CCC061574 for ; Wed, 31 Mar 2021 06:39:18 -0700 (PDT) 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 4F9S8g236Hz9sVb; Thu, 1 Apr 2021 00:39:15 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1617197955; bh=Wf6CnDfQWgn/hY7cq2C/wa4ZqetQCiDimtarRYDe7Fk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=c31RFkI19rETqVysZaOwWC8u9K7r/4KDXzwaRwGv/tAmIkdwj8sHpKkltWtHiSYgs 2ATqq1X/CTzmr+oqJkHXgyziksQ2ow6u+dKA7ViOnB/VC+7vAP7CCzXKwd5kDs16k2 c3AnFQ45Rp2R2QhI+8dz3+philYiBMbm6hBZ4A0DXixQiHlVlkDmGKNs6/KvGIsCQU W0efuCKCs+4owJLFCU8g+/kFoEDwNC40D7iysAbymsN0BhTk7Ps3sph7cFNWLD4CaV jirTAL/EnmFO3vmvxSxwrjjS7zsnqKnPYw/Wm/QYJ/BcAZIL3yVNbF3+Xsj3gZhJHZ oRWibay0XD2oA== From: Michael Ellerman To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/8xx: Load modules closer to kernel text In-Reply-To: References: Date: Thu, 01 Apr 2021 00:39:14 +1100 Message-ID: <87czvf788t.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 16MB seems kind of small. At least on 64-bit we could potentially have hundreds of MBs of modules. cheers