Re: [PATCH] arch, x86, irq: enable tracing of irq_move_cleanup_interrupt vector

[Nicolai Stange <nicstange@gmail.com>]

Please ignore this, I messed up the CC.

I will resend. Sorry for the noise!

Nicolai Stange <nicstange@gmail.com> writes:

> In commit cf910e83ae23 ("x86, trace: Add irq vector tracepoints"), support
> for the tracing of IRQ vectors had been introduced.
>
> For no apparent reason, irq_move_cleanup_interrupt had been left out from
> the list of traceable interrupt vectors, rendering it incomplete.
>
> Introduce support for tracing irq_move_cleanup_interrupt in the same way
> as done for the other vectors.
>
> Namely,
> - define a tracepoint event by means of DEFINE_IRQ_VECTOR_EVENT(),
> - add a tracing capable handler smp_trace_irq_move_cleanup_interrupt(),
> - introduce tracing versions of the IDT-referenced stubs which call into
>   the tracing version of the handler on both, x86 and x86_64,
> - finally, factor out the "real" interrupt handling code into the new
>   __smp_irq_move_cleanup_interrupt().
>
> Signed-off-by: Nicolai Stange <nicstange@gmail.com>
> ---
>  Patch is against tip x86/core.
>
>  Fully tested on x86_64, compiled on i386.
>
>  I do have analogue patches for the
>    kvm_posted_intr_ipi
>    kvm_posted_intr_wakeup_ipi
>  vectors as well. Due to lack of hardware, I'm unable to test them though.
>  If anybody with (/sys/module/kvm_intel/parameters/enable_apicv='Y') is
>  willing to help out, I'll gladly post them, too.
>
>  arch/x86/entry/entry_64.S                |  2 +-
>  arch/x86/include/asm/entry_arch.h        |  3 +--
>  arch/x86/include/asm/hw_irq.h            |  2 +-
>  arch/x86/include/asm/trace/irq_vectors.h |  6 ++++++
>  arch/x86/kernel/apic/vector.c            | 19 ++++++++++++++++---
>  5 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> index 8cb3e43..f7db1e0 100644
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -771,7 +771,7 @@ trace_apicinterrupt \num \sym
>  .endm
>  
>  #ifdef CONFIG_SMP
> -apicinterrupt3 IRQ_MOVE_CLEANUP_VECTOR		irq_move_cleanup_interrupt	smp_irq_move_cleanup_interrupt
> +apicinterrupt IRQ_MOVE_CLEANUP_VECTOR		irq_move_cleanup_interrupt	smp_irq_move_cleanup_interrupt
>  apicinterrupt3 REBOOT_VECTOR			reboot_interrupt		smp_reboot_interrupt
>  #endif
>  
> diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
> index df00299..a712d82 100644
> --- a/arch/x86/include/asm/entry_arch.h
> +++ b/arch/x86/include/asm/entry_arch.h
> @@ -13,8 +13,7 @@
>  BUILD_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR)
>  BUILD_INTERRUPT(call_function_interrupt,CALL_FUNCTION_VECTOR)
>  BUILD_INTERRUPT(call_function_single_interrupt,CALL_FUNCTION_SINGLE_VECTOR)
> -BUILD_INTERRUPT3(irq_move_cleanup_interrupt, IRQ_MOVE_CLEANUP_VECTOR,
> -		 smp_irq_move_cleanup_interrupt)
> +BUILD_INTERRUPT(irq_move_cleanup_interrupt, IRQ_MOVE_CLEANUP_VECTOR)
>  BUILD_INTERRUPT3(reboot_interrupt, REBOOT_VECTOR, smp_reboot_interrupt)
>  #endif
>  
> diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
> index 6615032..8fef2ac 100644
> --- a/arch/x86/include/asm/hw_irq.h
> +++ b/arch/x86/include/asm/hw_irq.h
> @@ -58,7 +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_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt
> +extern void trace_irq_move_cleanup_interrupt(void);
>  #define trace_reboot_interrupt  reboot_interrupt
>  #define trace_kvm_posted_intr_ipi kvm_posted_intr_ipi
>  #define trace_kvm_posted_intr_wakeup_ipi kvm_posted_intr_wakeup_ipi
> diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
> index 38a09a1..2dacb55 100644
> --- a/arch/x86/include/asm/trace/irq_vectors.h
> +++ b/arch/x86/include/asm/trace/irq_vectors.h
> @@ -112,6 +112,12 @@ DEFINE_IRQ_VECTOR_EVENT(deferred_error_apic);
>   */
>  DEFINE_IRQ_VECTOR_EVENT(thermal_apic);
>  
> +/*
> + * irq_move_cleanup - called when entering/exiting an IRQ move cleanup
> + * vector handler.
> + */
> +DEFINE_IRQ_VECTOR_EVENT(irq_move_cleanup);
> +
>  #undef TRACE_INCLUDE_PATH
>  #define TRACE_INCLUDE_PATH .
>  #define TRACE_INCLUDE_FILE irq_vectors
> diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
> index f813261..d0c1057 100644
> --- a/arch/x86/kernel/apic/vector.c
> +++ b/arch/x86/kernel/apic/vector.c
> @@ -20,6 +20,7 @@
>  #include <asm/i8259.h>
>  #include <asm/desc.h>
>  #include <asm/irq_remapping.h>
> +#include <asm/trace/irq_vectors.h>
>  
>  struct apic_chip_data {
>  	struct irq_cfg		cfg;
> @@ -532,12 +533,10 @@ void send_cleanup_vector(struct irq_cfg *cfg)
>  		__send_cleanup_vector(data);
>  }
>  
> -asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
> +static void __smp_irq_move_cleanup_interrupt(void)
>  {
>  	unsigned vector, me;
>  
> -	entering_ack_irq();
> -
>  	me = smp_processor_id();
>  	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
>  		int irq;
> @@ -587,7 +586,21 @@ asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
>  unlock:
>  		raw_spin_unlock(&desc->lock);
>  	}
> +}
> +
> +asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
> +{
> +	entering_ack_irq();
> +	__smp_irq_move_cleanup_interrupt();
> +	exiting_irq();
> +}
>  
> +asmlinkage __visible void smp_trace_irq_move_cleanup_interrupt(void)
> +{
> +	entering_ack_irq();
> +	trace_irq_move_cleanup_entry(IRQ_MOVE_CLEANUP_VECTOR);
> +	__smp_irq_move_cleanup_interrupt();
> +	trace_irq_move_cleanup_exit(IRQ_MOVE_CLEANUP_VECTOR);
>  	exiting_irq();
>  }