From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753047AbcFJJxX (ORCPT ); Fri, 10 Jun 2016 05:53:23 -0400 Received: from mout.kundenserver.de ([212.227.17.24]:56557 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbcFJJxV (ORCPT ); Fri, 10 Jun 2016 05:53:21 -0400 From: Arnd Bergmann To: Jason Baron Cc: akpm@linux-foundation.org, joe@perches.com, peterz@infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 4/4] dynamic_debug: add jump label support Date: Fri, 10 Jun 2016 11:54:03 +0200 Message-ID: <3796097.4dlb9d7Id8@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-22-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <587263b37406eda0d2ab84874a9fd4c81eaeca1d.1463778029.git.jbaron@akamai.com> References: <587263b37406eda0d2ab84874a9fd4c81eaeca1d.1463778029.git.jbaron@akamai.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:m4kCABB1fkO1IkYtbt21z5MkZpYj8CBQt7sTGGkMy9svJNU69uh urGu+2nyQvHhNGBUkECWgGYeLETioALNV/5QQJADVPzKDcn5D8BTB+rVHRpm3g1U+n8QMwJ TmRFi0YwF26QPmOF/vYPk2+pjn0CiXFaJbpiai/0QUa9Iu/AnM6Ce35bxRaLj8YG2yD9Ekj 654hI8YXrclbV7HnkPhQA== X-UI-Out-Filterresults: notjunk:1;V01:K0:GTiwugesGag=:rVJEXCmb+q/oeNMRT6Ss3y nnbC69EPcTeJJ8G4s4Puu55K8QeR5o20PrcRzZmBZwHX0MivaxtHbWAhWCRxVQ5iaSElPRzRe 7fC2QYNTTzN6JD9TE0Kdh+5lU20cfCi2++dy2ECkKeKIUxGtLBKdAPi03Le+Lrg9orKdjDsIe bQ4gPiaXwQle+XuSFv1ay+4EE7hQBX0Cdxdil8ZX/YaMJvuBbTIceML3YFljdVVFGS1N99Vag MoJZi5cFk4Of9ifqYa4IaitArwPzeMKKV3ig/WFjDhGhR6llCZf0u92C02AK8OVN3VS3rQT/a 0JhE31ONX3vjjbMoC46jLR2BtldA3XlpQlwCG8siPEpJ/PHNT/Ey16i8oupJSo39W4xfIAI4Z xqfwPLzGJoel+arh+B3friUu9nT26mvwX1yt26Qke7eVi3dXMTtnY9T4TobdSTTuo83ACXndA EAad1DGSoSA3ggQaZMQcFfOx+fXW9ZqPdvya/2YNmBkkB92DLIM/TbWjm9q3doOSIctd54bg3 LpZ/tsAcFnAyUqEYq/n7HFssjz7YKa00KHGCF7IDf61BIOHs49by/iXN/5JpMjuWFLNyGWnU2 yZc2BfOnuz+3PwetXkNza4eNsNVDRzNvM+UJ5SO3cwDUyeJ7w3iQLwm40Eh6xuGRHgw2r50AZ +iveIMl1I73VSpHFINrga7du1EiyrL4AWJlDcQubtGVdaiOgfcbJ5jt2d8IEOVhYWM43/bHWq 78nJhfXjaO5zCWem Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, May 20, 2016 5:16:36 PM CEST Jason Baron wrote: > Although dynamic debug is often only used for debug builds, sometimes its > enabled for production builds as well. Minimize its impact by using jump > labels. This reduces the text section by 7000+ bytes in the kernel image > below. It does increase data, but this should only be referenced when > changing the direction of the branches, and hence usually not in cache. > > text data bss dec hex filename > 8194852 4879776 925696 14000324 d5a0c4 vmlinux.pre > 8187337 4960224 925696 14073257 d6bda9 vmlinux.post > > Signed-off-by: Jason Baron > --- This causes problems for some of my randconfig builds, when a dynamic debug call is used inside of an __exit function: `.exit.text' referenced in section `__jump_table' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o `.exit.text' referenced in section `__jump_table' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o Arnd