From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753152AbeBIXA4 (ORCPT ); Fri, 9 Feb 2018 18:00:56 -0500 Received: from mga14.intel.com ([192.55.52.115]:32315 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752521AbeBIXAz (ORCPT ); Fri, 9 Feb 2018 18:00:55 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,485,1511856000"; d="scan'208";a="16668572" Date: Fri, 9 Feb 2018 15:00:41 -0800 From: Andi Kleen To: Chris Wilson Cc: Arnd Bergmann , x86@kernel.org, Nicolas Pitre , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] x86 bugfixes for LTO Message-ID: <20180209230041.GI10945@tassilo.jf.intel.com> References: <20180202145434.100626-1-arnd@arndb.de> <151821507347.9954.4785393248908071074@mail.alporthouse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <151821507347.9954.4785393248908071074@mail.alporthouse.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 09, 2018 at 10:24:33PM +0000, Chris Wilson wrote: > Quoting Arnd Bergmann (2018-02-02 14:54:28) > > Here are three bugfixes for x86 that I needed to get LTO-enabled > > kernels to build reliably. I'm not sure abouto that first one > > though. > > Is there a howto on how to build LTO kernels? I tried Andi's lto-415-2 > branch, but linking fails with lots of arcane PIE-vs-PIC errors. We are > wanting to investigate how we can use LTO to reduce our (i915.ko) module > size (by e.g. supporting a subset of chipsets). What are the errors? Kernel shouldn't use PIE or PIC -Andi