diff mbox

[01/18] Added hacking menu for override optimization by GCC.

Message ID 1329402705-25454-1-git-send-email-mail@smogura.eu
State Not Applicable, archived
Headers show

Commit Message

Radosław Smogura Feb. 16, 2012, 2:31 p.m. UTC 
From: mail@smogura.eu <mail@smogura.eu>

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.

Patch helps to debug kernel.
---
 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

Comments

Michal Nazarewicz Feb. 16, 2012, 9:59 p.m. UTC | #1 
On Thu, 16 Feb 2012 12:26:00 -0800, Radosław Smogura <mail@smogura.eu> wrote:

> On Thu, 16 Feb 2012 11:09:18 -0800, Michal Nazarewicz wrote:
>> On Thu, 16 Feb 2012 06:31:28 -0800, Radosław Smogura
>> <mail@smogura.eu> wrote:
>>> Supporting files, like Kconfig, Makefile are auto-generated due to
>>> large amount
>>> of available options.
>>
>> So why not run the script as part of make rather then store generated
>> files in
>> repository?
> Idea to run this script through make is quite good, and should work,
> because new mane will be generated before "config" starts.
>
> "Bashizms" are indeed unneeded, I will try to replace this with sed.

Uh? Why sed?
Radosław Smogura Feb. 16, 2012, 10:40 p.m. UTC | #2 
On Thu, 16 Feb 2012 13:59:29 -0800, Michal Nazarewicz wrote:
> On Thu, 16 Feb 2012 12:26:00 -0800, Radosław Smogura 
> <mail@smogura.eu> wrote:
>
>> On Thu, 16 Feb 2012 11:09:18 -0800, Michal Nazarewicz wrote:
>>> On Thu, 16 Feb 2012 06:31:28 -0800, Radosław Smogura
>>> <mail@smogura.eu> wrote:
>>>> Supporting files, like Kconfig, Makefile are auto-generated due to
>>>> large amount
>>>> of available options.
>>>
>>> So why not run the script as part of make rather then store 
>>> generated
>>> files in
>>> repository?
>> Idea to run this script through make is quite good, and should work,
>> because new mane will be generated before "config" starts.
>>
>> "Bashizms" are indeed unneeded, I will try to replace this with sed.
>
> Uh? Why sed?
There are some substitutions so I it will be better to use sed.
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Michal Nazarewicz Feb. 16, 2012, 11:11 p.m. UTC | #3 
On Thu, 16 Feb 2012 14:40:17 -0800, Radosław Smogura <mail@smogura.eu> wrote:

> On Thu, 16 Feb 2012 13:59:29 -0800, Michal Nazarewicz wrote:
>> On Thu, 16 Feb 2012 12:26:00 -0800, Radosław Smogura
>> <mail@smogura.eu> wrote:
>>
>>> On Thu, 16 Feb 2012 11:09:18 -0800, Michal Nazarewicz wrote:
>>>> On Thu, 16 Feb 2012 06:31:28 -0800, Radosław Smogura
>>>> <mail@smogura.eu> wrote:
>>>>> Supporting files, like Kconfig, Makefile are auto-generated due to
>>>>> large amount
>>>>> of available options.
>>>>
>>>> So why not run the script as part of make rather then store
>>>> generated
>>>> files in
>>>> repository?
>>> Idea to run this script through make is quite good, and should work,
>>> because new mane will be generated before "config" starts.
>>>
>>> "Bashizms" are indeed unneeded, I will try to replace this with sed.
>>
>> Uh? Why sed?
> There are some substitutions so I it will be better to use sed.

Do you mean this:

> cfg_o="${CFG_PREFIX}_${o//-/_}";

It can be achieved with “tr” like I've shown:

> cfg_o=$CFG_PREFIX_$(echo "$o" | tr '[:lower:]-' '[:upper:]_')
diff mbox

Patch

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 targets
 all: vmlinux
 
+ifdef CONFIG_HACK_OPTIM_FORCE_O1_LEVEL
+KBUILD_CFLAGS += -O1
+else
+
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS	+= -Os
 else
 KBUILD_CFLAGS	+= -O2
 endif
 
+endif
+
+# Include makefile for optimization override
+ifdef CONFIG_HACK_OPTIM
+include $(srctree)/scripts/Makefile.optim.inc
+endif
+
 include $(srctree)/arch/$(SRCARCH)/Makefile
 
 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"
 
 source "lib/Kconfig.kmemcheck"
 
+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
+# Distributed under GPL v2 License
+
+menuconfig HACK_OPTIM
+	bool "Allows 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
+	  more debug friendly, but with not guarentee
+	  about same runi, like production, kernel.
+
+	  If you say Y here probably You will want say
+	  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
+	  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_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
+	  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_combine_stack_adjustments
+	bool "Adds -fno-combine-stack-adjustments parameter to gcc invoke line."
+	---help---
+	  This will change how GCC optimize code. Code
+	  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_tree_dce
+	bool "Adds -fno-tree-dce parameter to gcc invoke line."
+	---help---
+	  This will change how GCC optimize code. Code
+	  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_tree_dominator_opts
+	bool "Adds -fno-tree-dominator-opts parameter to gcc invoke line."
+	---help---
+	  This will change how GCC optimize code. Code
+	  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
+	  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 += -fno-inline-functions-called-once
+endif
+
+ifdef CONFIG_HACK_OPTIM__fno_combine_stack_adjustments
+	KBUILD_CFLAGS += -fno-combine-stack-adjustments
+endif
+
+ifdef CONFIG_HACK_OPTIM__fno_tree_dce
+	KBUILD_CFLAGS += -fno-tree-dce
+endif
+
+ifdef CONFIG_HACK_OPTIM__fno_tree_dominator_opts
+	KBUILD_CFLAGS += -fno-tree-dominator-opts
+endif
+
+ifdef CONFIG_HACK_OPTIM__fno_dse
+	KBUILD_CFLAGS += -fno-dse
+endif
+
diff --git a/scripts/debug/make_config_optim.sh b/scripts/debug/make_config_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) Radosław Smogura, 2011
+
+# Prefix added for variable
+CFG_PREFIX="HACK_OPTIM"
+
+KCFG="Kconfig.debug.optim"
+MKFI="Makefile.optim.inc"
+
+OPTIMIZATIONS_PARAMS="-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" > $KCFG
+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" > $MKFI
+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" >> $KCFG
+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 $OPTIMIZATIONS_PARAMS ; do
+	cfg_o="${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" >> $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" >> $KCFG
+	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 += $o" >> $MKFI
+	echo "endif" >> $MKFI
+	echo  >> $MKFI
+done;
+echo "endif #${CFG_PREFIX}" >> $KCFG