x86/apic: Remove the duplicated tracing version of local_timer_interrupt()

The two NOP5s are noise in the rest of the work which is done by the timer
interrupt and modern CPUs are pretty good in optimizing NOPs anyway.

Get rid of the interrupt handler duplication and move the tracepoints into
the regular handler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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>
Link: http://lkml.kernel.org/r/20170828064956.751247330@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index d6dbafbd420737a5ea5363c700940acb22a8c358..44137bb1213680608906f99083e54effdd3d77e9 100644 (file)
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -48,7 +48,6 @@ extern asmlinkage void call_function_single_interrupt(void);
 
 #ifdef CONFIG_TRACING
 /* Interrupt handlers registered during init_IRQ */
-extern void trace_apic_timer_interrupt(void);
 extern void trace_x86_platform_ipi(void);
 extern void trace_error_interrupt(void);
 extern void trace_irq_work_interrupt(void);
@@ -59,6 +58,7 @@ extern void trace_threshold_interrupt(void);
 extern void trace_deferred_error_interrupt(void);
 extern void trace_call_function_interrupt(void);
 extern void trace_call_function_single_interrupt(void);
+#define trace_apic_timer_interrupt     apic_timer_interrupt
 #define trace_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt
 #define trace_reboot_interrupt  reboot_interrupt
 #define trace_kvm_posted_intr_ipi kvm_posted_intr_ipi

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 8996ef1eb39fad884bdc1667df83d76e419fa0f0..7a57b5418f6d9d7a547e085d54d5717cd007d98b 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1029,25 +1029,6 @@ __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 {
        struct pt_regs *old_regs = set_irq_regs(regs);
 
-       /*
-        * NOTE! We'd better ACK the irq immediately,
-        * because timer handling can be slow.
-        *
-        * update_process_times() expects us to have done irq_enter().
-        * Besides, if we don't timer interrupts ignore the global
-        * interrupt lock, which is the WrongThing (tm) to do.
-        */
-       entering_ack_irq();
-       local_apic_timer_interrupt();
-       exiting_irq();
-
-       set_irq_regs(old_regs);
-}
-
-__visible void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs)
-{
-       struct pt_regs *old_regs = set_irq_regs(regs);
-
        /*
         * NOTE! We'd better ACK the irq immediately,
         * because timer handling can be slow.