[PATCH 1/2] i386: ifdef out struct thread_struct::fs

[PATCH 1/2] i386: ifdef out struct thread_struct::fs

[Alexey Dobriyan]

After commit 464d1a78fbf8cf6c7fd970e7b3e2db50a320ce28 aka
"[PATCH] i386: Convert i386 PDA code to use %fs"
%fs saved during context switch moved from thread_struct to pt_regs
and value on thread_struct became unused.

I don't understand why .fs (OK, .gs first) initializer was added, kernel
clearly stopped touching it after the patch.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
 arch/x86/include/asm/processor.h |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c2cceae..a6732ff 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -428,7 +428,9 @@ struct thread_struct {
 	unsigned short		gsindex;
 #endif
 	unsigned long		ip;
+#ifdef CONFIG_X86_64
 	unsigned long		fs;
+#endif
 	unsigned long		gs;
 	/* Hardware debugging registers: */
 	unsigned long		debugreg0;
@@ -874,7 +876,6 @@ static inline void spin_lock_prefetch(const void *x)
 	.vm86_info		= NULL,					  \
 	.sysenter_cs		= __KERNEL_CS,				  \
 	.io_bitmap_ptr		= NULL,					  \
-	.fs			= __KERNEL_PERCPU,			  \
 }
 
 /*

[tip:x86/asm] x86, 32-bit: ifdef out struct thread_struct::fs

[tip-bot for Alexey Dobriyan]

Commit-ID:  d756f4adb9d8a86e347a2d5435bb5cc95744733e
Gitweb:     http://git.kernel.org/tip/d756f4adb9d8a86e347a2d5435bb5cc95744733e
Author:     Alexey Dobriyan <adobriyan@gmail.com>
AuthorDate: Mon, 4 May 2009 03:29:52 +0400
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 11 May 2009 16:23:54 +0200

x86, 32-bit: ifdef out struct thread_struct::fs

After commit 464d1a78fbf8cf6c7fd970e7b3e2db50a320ce28 aka
"[PATCH] i386: Convert i386 PDA code to use %fs"
%fs saved during context switch moved from thread_struct to pt_regs
and value on thread_struct became unused.

[ Impact: reduce thread_struct size on 32-bit ]

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: containers@lists.linux-foundation.org
LKML-Reference: <20090503232952.GI16631@x200.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/include/asm/processor.h |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c2cceae..a6732ff 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -428,7 +428,9 @@ struct thread_struct {
 	unsigned short		gsindex;
 #endif
 	unsigned long		ip;
+#ifdef CONFIG_X86_64
 	unsigned long		fs;
+#endif
 	unsigned long		gs;
 	/* Hardware debugging registers: */
 	unsigned long		debugreg0;
@@ -874,7 +876,6 @@ static inline void spin_lock_prefetch(const void *x)
 	.vm86_info		= NULL,					  \
 	.sysenter_cs		= __KERNEL_CS,				  \
 	.io_bitmap_ptr		= NULL,					  \
-	.fs			= __KERNEL_PERCPU,			  \
 }
 
 /*