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authorIngo Molnar <mingo@elte.hu>2008-05-17 08:30:07 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-17 15:59:58 +0200
commit34b2cd5b688b012975fcfc3b3970fc3508fa82c4 (patch)
tree018fee045ed5ebd2c6c654da53d94653dc48264c /arch/x86/kernel
parent573da4224e8c3800e613d715e909c3179a7e3cb2 (diff)
x86: PEBS cleanup
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/process_64.c29
1 files changed, 17 insertions, 12 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ad213494a22f..4a93c98a60a2 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -500,7 +500,6 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
{
struct thread_struct *prev, *next;
unsigned long debugctl;
- unsigned long ds_prev = 0, ds_next = 0;
prev = &prev_p->thread,
next = &next_p->thread;
@@ -508,17 +507,23 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
debugctl = prev->debugctlmsr;
#ifdef CONFIG_X86_DS
- if (prev->ds_ctx)
- ds_prev = (unsigned long)prev->ds_ctx->ds;
- if (next->ds_ctx)
- ds_next = (unsigned long)next->ds_ctx->ds;
-
- if (ds_next != ds_prev) {
- /* we clear debugctl to make sure DS
- * is not in use when we change it */
- debugctl = 0;
- update_debugctlmsr(0);
- wrmsrl(MSR_IA32_DS_AREA, ds_next);
+ {
+ unsigned long ds_prev = 0, ds_next = 0;
+
+ if (prev->ds_ctx)
+ ds_prev = (unsigned long)prev->ds_ctx->ds;
+ if (next->ds_ctx)
+ ds_next = (unsigned long)next->ds_ctx->ds;
+
+ if (ds_next != ds_prev) {
+ /*
+ * We clear debugctl to make sure DS
+ * is not in use when we change it:
+ */
+ debugctl = 0;
+ update_debugctlmsr(0);
+ wrmsrl(MSR_IA32_DS_AREA, ds_next);
+ }
}
#endif /* CONFIG_X86_DS */