From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 2/5] kbuild: allow archs to select build for link dead code/data elimination Date: Wed, 10 Aug 2016 00:29:29 +0200 Message-ID: <3076474.M72Ro1h3RL@wuerfel> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> <1882847.dG563Vieov@wuerfel> <20160809031605.GF3078@tassilo.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20160809031605.GF3078@tassilo.jf.intel.com> Sender: linux-kbuild-owner@vger.kernel.org To: Andi Kleen Cc: Alan Modra , linuxppc-dev@lists.ozlabs.org, Nicholas Piggin , linux-arch@vger.kernel.org, Stephen Rothwell , Nicolas Pitre , linux-kbuild@vger.kernel.org List-Id: linux-arch.vger.kernel.org On Monday, August 8, 2016 8:16:05 PM CEST Andi Kleen wrote: > > I don't understand what led Andi Kleen to also move .text.hot and > > .text.unlikely together with .text [2], but this may have > > been a related issue. > > > > [2] https://lkml.org/lkml/2015/7/19/377 > > The goal was just to move .hot and .unlikely all together, so that > they are clustered and use the minimum amount of cache. On x86 doesn't > matter where they are exactly, as long as each is together. > If they are not explicitely listed then the linker interleaves > them with the normal text, which defeats the purpose. I still don't see it, my reading of your patch is that you did the opposite, by changing the description that puts all .text.hot in front of .text, and all .text.unlikely after exit.text into one that mixes them with .text. What am I missing here? Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de ([212.227.126.187]:52619 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932360AbcHIW3k (ORCPT ); Tue, 9 Aug 2016 18:29:40 -0400 From: Arnd Bergmann Subject: Re: [PATCH 2/5] kbuild: allow archs to select build for link dead code/data elimination Date: Wed, 10 Aug 2016 00:29:29 +0200 Message-ID: <3076474.M72Ro1h3RL@wuerfel> In-Reply-To: <20160809031605.GF3078@tassilo.jf.intel.com> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> <1882847.dG563Vieov@wuerfel> <20160809031605.GF3078@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andi Kleen Cc: Alan Modra , linuxppc-dev@lists.ozlabs.org, Nicholas Piggin , linux-arch@vger.kernel.org, Stephen Rothwell , Nicolas Pitre , linux-kbuild@vger.kernel.org Message-ID: <20160809222929.sDA1ZAlpcS76tun0ff6t1GkAB39uTU33kU3tv65uHSw@z> On Monday, August 8, 2016 8:16:05 PM CEST Andi Kleen wrote: > > I don't understand what led Andi Kleen to also move .text.hot and > > .text.unlikely together with .text [2], but this may have > > been a related issue. > > > > [2] https://lkml.org/lkml/2015/7/19/377 > > The goal was just to move .hot and .unlikely all together, so that > they are clustered and use the minimum amount of cache. On x86 doesn't > matter where they are exactly, as long as each is together. > If they are not explicitely listed then the linker interleaves > them with the normal text, which defeats the purpose. I still don't see it, my reading of your patch is that you did the opposite, by changing the description that puts all .text.hot in front of .text, and all .text.unlikely after exit.text into one that mixes them with .text. What am I missing here? Arnd