[PATCH 4/5] x86-64: move unlazy_fpu() into lazy cpu state part of context switch

From: Jeremy Fitzhardinge
Date: Thu May 07 2009 - 20:35:30 EST


From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

Make sure that unlazy_fpu()'s stts gets batched along with the other
cpu state changes during context switch. (32-bit already does this.)

This makes sure it gets batched when running paravirtualized.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/kernel/process_64.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 2b659f2..534859b 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -422,6 +422,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)

load_TLS(next, cpu);

+ /* Must be after DS reload */
+ unlazy_fpu(prev_p);
+
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
@@ -462,9 +465,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
prev->gsindex = gsindex;

- /* Must be after DS reload */
- unlazy_fpu(prev_p);
-
/*
* Switch the PDA and FPU contexts.
*/
--
1.6.0.6

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