Re: ACPI in -pre7 builds with -Os

[Len Brown]

On Mon, 2003-10-13 at 19:14, J.A. Magallon wrote: 
> Hi all...
> 
> $subject:
> 
> drivers/acpi/Makefile:
> 
> ACPI_CFLAGS := -Os
> 
> Uh ?

-0s saves us ~20% text size.

cheers,
-Len

> --- Begin Message ---
> FYI,
> Building 2.4.23 with gcc -Os (as the source tree currently does) shrinks
> acpi text compared to gcc -O2.  How much -0s it saves depends on the
> version of gcc:
>
>
> 19.5% gcc version 3.2.2 20030222 (RHL 9.0)
> 20.6% gcc version 3.3.1 20030930 (Fedora Test3)
>
> as measured by text size for drivers/acpi.o with all modules excluded.
>
> cheers,
> -Len
>
> attached the script I use to measure acpi size, and the results for -O2
> and -Os on gcc 3.3.1.
>
> #!/bin/bash
> # summarize the size of ACPI in Linux
>
> # ACPI kernel modules
> MODULE_FILES=
> #for MODULE in drivers/acpi/*.ko ; do
> #	if [ -f $MODULE ] ; then
> #		MODULE_FILES="$MODULE_FILES $MODULE"
> #	fi
> #done
>
> MODULE_LIST="ac asus_acpi battery button fan processor thermal toshiba_acpi"
> if [ "$MODULE_FILES" = "" ] ; then
> 	DIR=drivers/acpi
> 	for MODULE in $MODULE_LIST; do
> 		if [ -f $DIR/$MODULE.o ] ; then
> 			MODULE_FILES="$MODULE_FILES $DIR/$MODULE.o"
> 		fi
> 	done
> fi
>
>
> if [ "$MODULE_FILES" != "" ] ; then
> 	echo Loadable Module Sizes:
> 	size $MODULE_FILES
> 	echo
> 	echo Static Kernel Size:
> fi
>
> # ACPI obj files outside drivers/acpi
> STATIC_FILES=
> # acpi objects in base kernel
> for FILE in arch/i386/kernel/acpi/built-in.o arch/i386/kernel/acpi*.o ; do
> 	if [ -f $FILE ] ; then
> 		STATIC_FILES="$STATIC_FILES $FILE"
> 	fi
> done
>
>
> # ACPI core driver
> DRIVER_DIR=drivers/acpi
> for DRIVER_OBJECT in acpi.o built-in.o ; do
> 	if [ -f $DRIVER_DIR/$DRIVER_OBJECT ] ; then
> 		STATIC_FILES="$STATIC_FILES $DRIVER_DIR/$DRIVER_OBJECT"
> 	fi
> done
>
>
> NUM_FILES=`echo $STATIC_FILES | wc -w`
> if [ $NUM_FILES == 0 ] ; then
> 	echo $0: no acpi code present
> elif [ $NUM_FILES == 1 ] ; then
> 	size $STATIC_FILES
> else
> 	size -t $STATIC_FILES
> fi
>
> Loadable Module Sizes:
>    text	   data	    bss	    dec	    hex	filename
>    1712	    212	     12	   1936	    790	drivers/acpi/ac.o
>    8628	    884	     24	   9536	   2540	drivers/acpi/asus_acpi.o
>    6220	    212	     12	   6444	   192c	drivers/acpi/battery.o
>    2532	    212	     24	   2768	    ad0	drivers/acpi/button.o
>    1423	    212	     12	   1647	    66f	drivers/acpi/fan.o
>    9643	    212	    172	  10027	   272b	drivers/acpi/processor.o
>    7543	    212	     16	   7771	   1e5b	drivers/acpi/thermal.o
>    3451	     72	     24	   3547	    ddb	drivers/acpi/toshiba_acpi.o
>
> Static Kernel Size:
>    text	   data	    bss	    dec	    hex	filename
>    3214	      8	    136	   3358	    d1e	arch/i386/kernel/acpi.o
>     917	     52	      0	    969	    3c9	arch/i386/kernel/acpi_wakeup.o
>  178384	   4194	   4888	 187466	  2dc4a	drivers/acpi/acpi.o
>  182515	   4254	   5024	 191793	  2ed31	(TOTALS)
> Loadable Module Sizes:
>    text	   data	    bss	    dec	    hex	filename
>    1294	    212	     12	   1518	    5ee	drivers/acpi/ac.o
>    7249	    884	     24	   8157	   1fdd	drivers/acpi/asus_acpi.o
>    5297	    212	     12	   5521	   1591	drivers/acpi/battery.o
>    2031	    212	     24	   2267	    8db	drivers/acpi/button.o
>    1098	    212	     12	   1322	    52a	drivers/acpi/fan.o
>    7905	    212	    172	   8289	   2061	drivers/acpi/processor.o
>    5894	    212	     16	   6122	   17ea	drivers/acpi/thermal.o
>    2669	     72	     24	   2765	    acd	drivers/acpi/toshiba_acpi.o
>
> Static Kernel Size:
>    text	   data	    bss	    dec	    hex	filename
>    3214	      8	    136	   3358	    d1e	arch/i386/kernel/acpi.o
>     917	     52	      0	    969	    3c9	arch/i386/kernel/acpi_wakeup.o
>  141584	   4194	   4888	 150666	  24c8a	drivers/acpi/acpi.o
>  145715	   4254	   5024	 154993	  25d71	(TOTALS)
>
> --- End Message ---