[PATCH 3/8] x86, i387.c: thread xstate is initialized only on BSP once

From: Fenghua Yu
Date: Wed Oct 05 2011 - 12:55:35 EST


From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

init_thread_xstate() is only called on BSP once to avoid to override
xstate_size.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
arch/x86/kernel/i387.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 739d859..de2b48a 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -93,6 +93,7 @@ void __cpuinit fpu_init(void)
{
unsigned long cr0;
unsigned long cr4_mask = 0;
+ static int once;

if (cpu_has_fxsr)
cr4_mask |= X86_CR4_OSFXSR;
@@ -107,8 +108,14 @@ void __cpuinit fpu_init(void)
cr0 |= X86_CR0_EM;
write_cr0(cr0);

- if (!smp_processor_id())
+ /*
+ * init_thread_xstate is only called on BSP once to avoid to override
+ * xstate_size.
+ */
+ if (!smp_processor_id() && once) {
+ once = 0;
init_thread_xstate();
+ }

mxcsr_feature_mask_init();
/* clean state in init */
--
1.6.0.3

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