[patch 27/29] x86: Use generic init_task

From: Thomas Gleixner
Date: Mon Apr 30 2012 - 16:17:32 EST


Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
arch/x86/Kconfig | 1 +
arch/x86/Makefile | 1 -
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/init_task.c | 42 ------------------------------------------
arch/x86/kernel/process.c | 9 +++++++++
5 files changed, 11 insertions(+), 44 deletions(-)

Index: tip/arch/x86/Kconfig
===================================================================
--- tip.orig/arch/x86/Kconfig
+++ tip/arch/x86/Kconfig
@@ -83,6 +83,7 @@ config X86
select GENERIC_IOMAP
select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
select GENERIC_SMP_IDLE_THREAD
+ select HAVE_GENERIC_INIT_TASK

config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
Index: tip/arch/x86/Makefile
===================================================================
--- tip.orig/arch/x86/Makefile
+++ tip/arch/x86/Makefile
@@ -146,7 +146,6 @@ archheaders:
head-y := arch/x86/kernel/head_$(BITS).o
head-y += arch/x86/kernel/head$(BITS).o
head-y += arch/x86/kernel/head.o
-head-y += arch/x86/kernel/init_task.o

libs-y += arch/x86/lib/

Index: tip/arch/x86/kernel/Makefile
===================================================================
--- tip.orig/arch/x86/kernel/Makefile
+++ tip/arch/x86/kernel/Makefile
@@ -2,7 +2,7 @@
# Makefile for the linux kernel.
#

-extra-y := head_$(BITS).o head$(BITS).o head.o init_task.o vmlinux.lds
+extra-y := head_$(BITS).o head$(BITS).o head.o vmlinux.lds

CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE)

Index: tip/arch/x86/kernel/init_task.c
===================================================================
--- tip.orig/arch/x86/kernel/init_task.c
+++ /dev/null
@@ -1,42 +0,0 @@
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/desc.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
- { INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);
-
-/*
- * per-CPU TSS segments. Threads are completely 'soft' on Linux,
- * no more per-task TSS's. The TSS size is kept cacheline-aligned
- * so they are allowed to end up in the .data..cacheline_aligned
- * section. Since TSS's are completely CPU-local, we want them
- * on exact cacheline boundaries, to eliminate cacheline ping-pong.
- */
-DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, init_tss) = INIT_TSS;
-
Index: tip/arch/x86/kernel/process.c
===================================================================
--- tip.orig/arch/x86/kernel/process.c
+++ tip/arch/x86/kernel/process.c
@@ -27,6 +27,15 @@
#include <asm/debugreg.h>
#include <asm/nmi.h>

+/*
+ * per-CPU TSS segments. Threads are completely 'soft' on Linux,
+ * no more per-task TSS's. The TSS size is kept cacheline-aligned
+ * so they are allowed to end up in the .data..cacheline_aligned
+ * section. Since TSS's are completely CPU-local, we want them
+ * on exact cacheline boundaries, to eliminate cacheline ping-pong.
+ */
+DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, init_tss) = INIT_TSS;
+
#ifdef CONFIG_X86_64
static DEFINE_PER_CPU(unsigned char, is_idle);
static ATOMIC_NOTIFIER_HEAD(idle_notifier);


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