From 22f0a27367742f65130c0fb25ef00f7297e032c1 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Mon, 17 Jun 2013 18:34:14 -0400 Subject: [PATCH] init.h: remove __cpuinit sections from the kernel The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. As an interim step, we can dummy out the macros to be no-ops, and this will allow us to avoid a giant tree-wide patch, and instead we can feed in smaller chunks mainly via the arch/ trees. This is in keeping with commit 78d86c213f28193082b5d8a1a424044b7ba406f1 ("init.h: Remove __dev* sections from the kernel") We don't strictly need to dummy out the macros to do this, but if we don't then some harmless section mismatch warnings may temporarily result. For example, notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit. And hence the calling functions in the arch specific code are also expected to be __cpuinit -- if not, then we get the section mismatch warning. Two of the three __CPUINIT variants are not used whatsoever, and so they are simply removed directly at this point in time. [1] https://lkml.org/lkml/2013/5/20/589 Signed-off-by: Paul Gortmaker --- include/linux/init.h | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index 861814710d52..e73f2b708525 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -93,13 +93,13 @@ #define __exit __section(.exit.text) __exitused __cold notrace -/* Used for HOTPLUG_CPU */ -#define __cpuinit __section(.cpuinit.text) __cold notrace -#define __cpuinitdata __section(.cpuinit.data) -#define __cpuinitconst __constsection(.cpuinit.rodata) -#define __cpuexit __section(.cpuexit.text) __exitused __cold notrace -#define __cpuexitdata __section(.cpuexit.data) -#define __cpuexitconst __constsection(.cpuexit.rodata) +/* temporary, until all users are removed */ +#define __cpuinit +#define __cpuinitdata +#define __cpuinitconst +#define __cpuexit +#define __cpuexitdata +#define __cpuexitconst /* Used for MEMORY_HOTPLUG */ #define __meminit __section(.meminit.text) __cold notrace @@ -118,9 +118,8 @@ #define __INITRODATA .section ".init.rodata","a",%progbits #define __FINITDATA .previous -#define __CPUINIT .section ".cpuinit.text", "ax" -#define __CPUINITDATA .section ".cpuinit.data", "aw" -#define __CPUINITRODATA .section ".cpuinit.rodata", "a" +/* temporary, until all users are removed */ +#define __CPUINIT #define __MEMINIT .section ".meminit.text", "ax" #define __MEMINITDATA .section ".meminit.data", "aw" -- 2.34.1