x86/i387.c: Initialize thread xstate only on CPU0 only once

init_thread_xstate() is only called once to avoid overriding xstate_size during
boot time or during CPU hotplug.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-14-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 675a05012449..245a71db401a 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -175,7 +175,11 @@ void __cpuinit fpu_init(void)
                 cr0 |= X86_CR0_EM;
         write_cr0(cr0);
 
-        if (!smp_processor_id())
+        /*
+         * init_thread_xstate is only called once to avoid overriding
+         * xstate_size during boot time or during CPU hotplug.
+         */
+        if (xstate_size == 0)
                 init_thread_xstate();
 
         mxcsr_feature_mask_init();