[tip:x86/apic] x86/smp: Remove pointless duplicated interrupt code

tip-bot for Thomas Gleixner
2017-08-29T11:13:56Z

Commit-ID: 85b77cdd8fbd163d65f340e3f6578c50031af960
Gitweb: http://git.kernel.org/tip/85b77cdd8fbd163d65f340e3f6578c50031af960
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 28 Aug 2017 08:47:29 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 29 Aug 2017 11:42:27 +0200

x86/smp: Remove pointless duplicated interrupt code

Two NOP5s are really a good tradeoff vs. the unholy IDT switching mess,
which duplicates code all over the place. The rescheduling interrupt gets
optimized in a later step.

Make the ordering of function call and statistics increment the same as in
other places. Calculate stats first, then do the function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.222101344@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/hw_irq.h | 4 ++--
arch/x86/kernel/smp.c | 43 +++++++------------------------------------
2 files changed, 9 insertions(+), 38 deletions(-)

diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 5f042ec..8fb6c22 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -49,8 +49,8 @@ extern asmlinkage void call_function_single_interrupt(void);
#ifdef CONFIG_TRACING
/* Interrupt handlers registered during init_IRQ */
extern void trace_reschedule_interrupt(void);
-extern void trace_call_function_interrupt(void);
-extern void trace_call_function_single_interrupt(void);
+#define trace_call_function_interrupt call_function_interrupt
+#define trace_call_function_single_interrupt call_function_single_interrupt
#define trace_thermal_interrupt thermal_interrupt
#define trace_threshold_interrupt threshold_interrupt
#define trace_deferred_error_interrupt deferred_error_interrupt
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index d798c0d..fb49e10 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -281,57 +281,28 @@ __visible void __irq_entry smp_trace_reschedule_interrupt(struct pt_regs *regs)
*/
ipi_entering_ack_irq();
trace_reschedule_entry(RESCHEDULE_VECTOR);
- __smp_reschedule_interrupt();
+ inc_irq_stat(irq_resched_count);
+ scheduler_ipi();
trace_reschedule_exit(RESCHEDULE_VECTOR);
exiting_irq();
- /*
- * KVM uses this interrupt to force a cpu out of guest mode
- */
-}
-
-static inline void __smp_call_function_interrupt(void)
-{
- generic_smp_call_function_interrupt();
- inc_irq_stat(irq_call_count);
}

__visible void __irq_entry smp_call_function_interrupt(struct pt_regs *regs)
{
ipi_entering_ack_irq();
- __smp_call_function_interrupt();
- exiting_irq();
-}
-
-__visible void __irq_entry
-smp_trace_call_function_interrupt(struct pt_regs *regs)
-{
- ipi_entering_ack_irq();
trace_call_function_entry(CALL_FUNCTION_VECTOR);
- __smp_call_function_interrupt();
- trace_call_function_exit(CALL_FUNCTION_VECTOR);
- exiting_irq();
-}
-
-static inline void __smp_call_function_single_interrupt(void)
-{
- generic_smp_call_function_single_interrupt();
inc_irq_stat(irq_call_count);
-}
-
-__visible void __irq_entry
-smp_call_function_single_interrupt(struct pt_regs *regs)
-{
- ipi_entering_ack_irq();
- __smp_call_function_single_interrupt();
+ generic_smp_call_function_interrupt();
+ trace_call_function_exit(CALL_FUNCTION_VECTOR);
exiting_irq();
}

-__visible void __irq_entry
-smp_trace_call_function_single_interrupt(struct pt_regs *regs)
+__visible void __irq_entry smp_call_function_single_interrupt(struct pt_regs *r)
{
ipi_entering_ack_irq();
trace_call_function_single_entry(CALL_FUNCTION_SINGLE_VECTOR);
- __smp_call_function_single_interrupt();
+ inc_irq_stat(irq_call_count);
+ generic_smp_call_function_single_interrupt();
trace_call_function_single_exit(CALL_FUNCTION_SINGLE_VECTOR);
exiting_irq();
}