linux-kernel - [PATCH 027/208] x86/fpu: Remove the free_thread

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Date:	Tue,  5 May 2015 18:24:07 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	linux-kernel@...r.kernel.org
Cc:	Andy Lutomirski <luto@...capital.net>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Fenghua Yu <fenghua.yu@...el.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Oleg Nesterov <oleg@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 027/208] x86/fpu: Remove the free_thread_xstate() complication

Use fpstate_free() directly to manage FPU state.

Only process.c was using this method, so this is a speedup as well,
as it removes the extra function call and related clobbers.

Reviewed-by: Borislav Petkov <bp@...en8.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/include/asm/processor.h | 1 -
 arch/x86/kernel/process.c        | 9 ++-------
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 6b75c4b927ec..fef8db024ece 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -362,7 +362,6 @@ DECLARE_PER_CPU(struct irq_stack *, softirq_stack);
 #endif	/* X86_64 */
 
 extern unsigned int xstate_size;
-extern void free_thread_xstate(struct task_struct *);
 extern struct kmem_cache *task_xstate_cachep;
 
 struct perf_event;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 5daa6547fdc7..a9bff373f7eb 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -99,14 +99,9 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 	return 0;
 }
 
-void free_thread_xstate(struct task_struct *tsk)
-{
-	fpstate_free(&tsk->thread.fpu);
-}
-
 void arch_release_task_struct(struct task_struct *tsk)
 {
-	free_thread_xstate(tsk);
+	fpstate_free(&tsk->thread.fpu);
 }
 
 void arch_task_cache_init(void)
@@ -154,7 +149,7 @@ void flush_thread(void)
 	if (!use_eager_fpu()) {
 		/* FPU state will be reallocated lazily at the first use. */
 		drop_fpu(tsk);
-		free_thread_xstate(tsk);
+		fpstate_free(&tsk->thread.fpu);
 	} else if (!used_math()) {
 		/* kthread execs. TODO: cleanup this horror. */
 		if (WARN_ON(fpstate_alloc_init(tsk)))
-- 
2.1.0

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