From: Randy Dunlap Subject: Re: [PATCH 01/18] Added hacking menu for override optimization by GCC. Date: Thu, 16 Feb 2012 07:44:54 -0800 Message-ID: <4F3D2476.4030409@xenotime.net> References: <1329402705-25454-1-git-send-email-mail@smogura.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: linux-mm@kvack.org, Yongqiang Yang , linux-ext4@vger.kernel.org To: =?UTF-8?B?UmFkb3PFgmF3IFNtb2d1cmE=?= Return-path: In-Reply-To: <1329402705-25454-1-git-send-email-mail@smogura.eu> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On 02/16/2012 06:31 AM, Rados=C5=82aw Smogura wrote: > From: mail@smogura.eu >=20 > This patch gives ability for add some "-fno-..." options for GCC > and to force -O1 optimization. Supporting files, like Kconfig, Makefile > are auto-generated due to large amount of available options. >=20 > Patch helps to debug kernel. Note: I only see patches 1-10. I fix a few typos below (comments in the generated files only). > --- > Makefile | 11 ++++ > lib/Kconfig.debug | 2 + > lib/Kconfig.debug.optim | 102 ++++++++++++++++++++++++++++= ++++++++ > scripts/Makefile.optim.inc | 23 ++++++++ > scripts/debug/make_config_optim.sh | 88 ++++++++++++++++++++++++++++= +++ > 5 files changed, 226 insertions(+), 0 deletions(-) > create mode 100644 lib/Kconfig.debug.optim > create mode 100644 scripts/Makefile.optim.inc > create mode 100644 scripts/debug/make_config_optim.sh >=20 > diff --git a/Makefile b/Makefile > index 7c44b67..bc9a961 100644 > --- a/Makefile > +++ b/Makefile > @@ -558,12 +558,23 @@ endif # $(dot-config) > # Defaults to vmlinux, but the arch makefile usually adds further targ= ets > all: vmlinux > =20 > +ifdef CONFIG_HACK_OPTIM_FORCE_O1_LEVEL > +KBUILD_CFLAGS +=3D -O1 > +else > + > ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE > KBUILD_CFLAGS +=3D -Os > else > KBUILD_CFLAGS +=3D -O2 > endif > =20 > +endif > + > +# Include makefile for optimization override > +ifdef CONFIG_HACK_OPTIM > +include $(srctree)/scripts/Makefile.optim.inc > +endif > + > include $(srctree)/arch/$(SRCARCH)/Makefile > =20 > ifneq ($(CONFIG_FRAME_WARN),0) > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 8745ac7..928265e 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1274,5 +1274,7 @@ source "lib/Kconfig.kgdb" > =20 > source "lib/Kconfig.kmemcheck" > =20 > +source "lib/Kconfig.debug.optim" > + > config TEST_KSTRTOX > tristate "Test kstrto*() family of functions at runtime" > diff --git a/lib/Kconfig.debug.optim b/lib/Kconfig.debug.optim > new file mode 100644 > index 0000000..09b1012 > --- /dev/null > +++ b/lib/Kconfig.debug.optim > @@ -0,0 +1,102 @@ > +# This file was auto generated. It's utility configuration ^^^^^^^^^^^^^^^^^^^^^^^^^^ That sentence(?) (fragment?) is not helpful. I would drop it. > +# Distributed under GPL v2 License > + > +menuconfig HACK_OPTIM > + bool "Allows to override GCC optimization" Allows the user to override GCC optimization > + depends on DEBUG_KERNEL && EXPERIMENTAL > + help > + If you say Y here you will be able to override > + how GCC optimize kernel code. This will create optimizes > + more debug friendly, but with not guarentee friendly code, but will not guarantee > + about same runi, like production, kernel. the same running, like a production kernel. > + > + If you say Y here probably You will want say you will want to say Y > + for all suboptions for all suboptions. > + > +if HACK_OPTIM > + > +config HACK_OPTIM_FORCE_O1_LEVEL > + bool "Forces -O1 optimization level" > + ---help--- > + This will change how GCC optimize code. Code optimizes > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not will run differently than normal, > + some bugs or errors. Refere to GCC manual for Refer > + more details. > + > + You SHOULD say N here. > + > +config HACK_OPTIM__fno_inline_functions_called_once > + bool "Adds -fno-inline-functions-called-once parameter to gcc invoke = line." > + ---help--- > + This will change how GCC optimize code. Code optimizes > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not will run differently than normal, > + some bugs or errors. Refere to GCC manual for Refer > + more details. > + > + You SHOULD say N here. > + > +config HACK_OPTIM__fno_combine_stack_adjustments > + bool "Adds -fno-combine-stack-adjustments parameter to gcc invoke lin= e." > + ---help--- > + This will change how GCC optimize code. Code optimizes > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not will run differently than normal, > + some bugs or errors. Refere to GCC manual for Refer > + more details. > + > + You SHOULD say N here. > + > +config HACK_OPTIM__fno_tree_dce > + bool "Adds -fno-tree-dce parameter to gcc invoke line." > + ---help--- > + This will change how GCC optimize code. Code optimizes > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not will run differently than normal, > + some bugs or errors. Refere to GCC manual for Refer > + more details. > + > + You SHOULD say N here. > + > +config HACK_OPTIM__fno_tree_dominator_opts > + bool "Adds -fno-tree-dominator-opts parameter to gcc invoke line." > + ---help--- > + This will change how GCC optimize code. Code same ... > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not > + some bugs or errors. Refere to GCC manual for > + more details. > + > + You SHOULD say N here. > + > +config HACK_OPTIM__fno_dse > + bool "Adds -fno-dse parameter to gcc invoke line." > + ---help--- > + This will change how GCC optimize code. Code same ... > + may be slower and larger but will be more debug > + "friendly". > + > + In some cases there is low chance that kernel > + will run different then normal, reporting or not > + some bugs or errors. Refere to GCC manual for > + more details. > + > + You SHOULD say N here. > + > +endif #HACK_OPTIM > diff --git a/scripts/Makefile.optim.inc b/scripts/Makefile.optim.inc > new file mode 100644 > index 0000000..e78cc92 > --- /dev/null > +++ b/scripts/Makefile.optim.inc > @@ -0,0 +1,23 @@ > +# This file was auto generated. It's utility configuration > +# Distributed under GPL v2 License > + > +ifdef CONFIG_HACK_OPTIM__fno_inline_functions_called_once > + KBUILD_CFLAGS +=3D -fno-inline-functions-called-once > +endif > + > +ifdef CONFIG_HACK_OPTIM__fno_combine_stack_adjustments > + KBUILD_CFLAGS +=3D -fno-combine-stack-adjustments > +endif > + > +ifdef CONFIG_HACK_OPTIM__fno_tree_dce > + KBUILD_CFLAGS +=3D -fno-tree-dce > +endif > + > +ifdef CONFIG_HACK_OPTIM__fno_tree_dominator_opts > + KBUILD_CFLAGS +=3D -fno-tree-dominator-opts > +endif > + > +ifdef CONFIG_HACK_OPTIM__fno_dse > + KBUILD_CFLAGS +=3D -fno-dse > +endif > + > diff --git a/scripts/debug/make_config_optim.sh b/scripts/debug/make_co= nfig_optim.sh > new file mode 100644 > index 0000000..26865923 > --- /dev/null > +++ b/scripts/debug/make_config_optim.sh > @@ -0,0 +1,88 @@ > +#!/bin/sh > + > +## Utility script for generating optimization override options > +## for kernel compilation. > +## > +## Distributed under GPL v2 license > +## (c) Rados=C5=82aw Smogura, 2011 > + > +# Prefix added for variable > +CFG_PREFIX=3D"HACK_OPTIM" > + > +KCFG=3D"Kconfig.debug.optim" > +MKFI=3D"Makefile.optim.inc" > + > +OPTIMIZATIONS_PARAMS=3D"-fno-inline-functions-called-once \ > + -fno-combine-stack-adjustments \ > + -fno-tree-dce \ > + -fno-tree-dominator-opts \ > + -fno-dse " > + > +echo "# This file was auto generated. It's utility configuration" > $K= CFG > +echo "# Distributed under GPL v2 License" >> $KCFG > +echo >> $KCFG > +echo "menuconfig ${CFG_PREFIX}" >> $KCFG > +echo -e "\tbool \"Allows to override GCC optimization\"" >> $KCFG > +echo -e "\tdepends on DEBUG_KERNEL && EXPERIMENTAL" >> $KCFG > +echo -e "\thelp" >> $KCFG > +echo -e "\t If you say Y here you will be able to override" >> $KCFG > +echo -e "\t how GCC optimize kernel code. This will create" >> $KCFG > +echo -e "\t more debug friendly, but with not guarentee" >> $KCFG > +echo -e "\t about same runi, like production, kernel." >> $KCFG > +echo >> $KCFG > +echo -e "\t If you say Y here probably You will want say" >> $KCFG > +echo -e "\t for all suboptions" >> $KCFG > +echo >> $KCFG > +echo "if ${CFG_PREFIX}" >> $KCFG > +echo >> $KCFG > + > +echo "# This file was auto generated. It's utility configuration" > $M= KFI > +echo "# Distributed under GPL v2 License" >> $MKFI > +echo >> $MKFI > + > +# Insert standard override optimization level > +# This is exception, and this value will not be included > +# in auto generated makefile. Support for this value > +# is hard coded in main Makefile. > +echo -e "config ${CFG_PREFIX}_FORCE_O1_LEVEL" >> $KCFG > +echo -e "\tbool \"Forces -O1 optimization level\"" >> $KCFG > +echo -e "\t---help---" >> $KCFG > +echo -e "\t This will change how GCC optimize code. Code" >> $KCFG > +echo -e "\t may be slower and larger but will be more debug" >> $KCFG > +echo -e "\t \"friendly\"." >> $KCFG > +echo >> $KCFG > +echo -e "\t In some cases there is low chance that kernel" >> $KCFG > +echo -e "\t will run different then normal, reporting or not" >> $KCF= G > +echo -e "\t some bugs or errors. Refere to GCC manual for" >> $KCFG > +echo -e "\t more details." >> $KCFG > +echo >> $KCFG > +echo -e "\t You SHOULD say N here." >> $KCFG > +echo >> $KCFG > + > +for o in $OPTIMIZATIONS_PARAMS ; do > + cfg_o=3D"${CFG_PREFIX}_${o//-/_}"; > + echo "Processing param ${o} config variable will be $cfg_o"; > + > + # Generate kconfig entry > + echo -e "config ${cfg_o}" >> $KCFG > + echo -e "\tbool \"Adds $o parameter to gcc invoke line.\"" >> $KCFG > + echo -e "\t---help---" >> $KCFG > + echo -e "\t This will change how GCC optimize code. Code" >> $KCFG > + echo -e "\t may be slower and larger but will be more debug" >> $KCF= G > + echo -e "\t \"friendly\"." >> $KCFG > + echo >> $KCFG > + echo -e "\t In some cases there is low chance that kernel" >> $KCFG > + echo -e "\t will run different then normal, reporting or not" >> $KC= FG > + echo -e "\t some bugs or errors. Refere to GCC manual for" >> $KCFG > + echo -e "\t more details." >> $KCFG > + echo >> $KCFG > + echo -e "\t You SHOULD say N here." >> $KCFG > + echo >> $KCFG > + > + #Generate Make for include > + echo "ifdef CONFIG_${cfg_o}" >> $MKFI > + echo -e "\tKBUILD_CFLAGS +=3D $o" >> $MKFI > + echo "endif" >> $MKFI > + echo >> $MKFI > +done; > +echo "endif #${CFG_PREFIX}" >> $KCFG --=20 ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code = *** -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter= .ca/ Don't email: email@kvack.org