[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20170825171010.40a7f783@gandalf.local.home>
Date: Fri, 25 Aug 2017 17:10:10 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: LKML <linux-kernel@...r.kernel.org>,
Ingo Molnar <mingo@...nel.org>, Peter Anvin <hpa@...or.com>,
Peter Zijlstra <peterz@...radead.org>,
Andy Lutomirski <luto@...nel.org>,
Borislav Petkov <bp@...en8.de>
Subject: Re: [patch 14/41] x86/smp: Use static key for reschedule interrupt
tracing
On Fri, 25 Aug 2017 22:07:33 +0200 (CEST)
Thomas Gleixner <tglx@...utronix.de> wrote:
> Fixed up version below.
>
Reviewed-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
-- Steve
> Thanks,
>
> tglx
> 8<---------------------
> --- a/arch/x86/include/asm/hw_irq.h
> +++ b/arch/x86/include/asm/hw_irq.h
> @@ -48,7 +48,7 @@ extern asmlinkage void call_function_sin
>
> #ifdef CONFIG_TRACING
> /* Interrupt handlers registered during init_IRQ */
> -extern void trace_reschedule_interrupt(void);
> +#define trace_reschedule_interrupt reschedule_interrupt
> #define trace_call_function_interrupt call_function_interrupt
> #define trace_call_function_single_interrupt call_function_single_interrupt
> #define trace_thermal_interrupt thermal_interrupt
> --- a/arch/x86/kernel/smp.c
> +++ b/arch/x86/kernel/smp.c
> @@ -254,37 +254,27 @@ static void native_stop_other_cpus(int w
> }
>
> /*
> - * Reschedule call back.
> + * Reschedule call back. KVM uses this interrupt to force a cpu out of
> + * guest mode
> */
> -static inline void __smp_reschedule_interrupt(void)
> -{
> - inc_irq_stat(irq_resched_count);
> - scheduler_ipi();
> -}
> -
> __visible void __irq_entry smp_reschedule_interrupt(struct pt_regs *regs)
> {
> ack_APIC_irq();
> - __smp_reschedule_interrupt();
> - /*
> - * KVM uses this interrupt to force a cpu out of guest mode
> - */
> -}
> -
> -__visible void __irq_entry smp_trace_reschedule_interrupt(struct pt_regs *regs)
> -{
> - /*
> - * Need to call irq_enter() before calling the trace point.
> - * __smp_reschedule_interrupt() calls irq_enter/exit() too (in
> - * scheduler_ipi(). This is OK, since those functions are allowed
> - * to nest.
> - */
> - ipi_entering_ack_irq();
> - trace_reschedule_entry(RESCHEDULE_VECTOR);
> inc_irq_stat(irq_resched_count);
> +
> + if (trace_irqvectors_enabled()) {
> + /*
> + * scheduler_ipi() might call irq_enter() as well, but
> + * nested calls are fine.
> + */
> + irq_enter();
> + trace_reschedule_entry(RESCHEDULE_VECTOR);
> + scheduler_ipi();
> + trace_reschedule_exit(RESCHEDULE_VECTOR);
> + irq_exit();
> + return;
> + }
> scheduler_ipi();
> - trace_reschedule_exit(RESCHEDULE_VECTOR);
> - exiting_irq();
> }
>
> __visible void __irq_entry smp_call_function_interrupt(struct pt_regs *regs)
>
Powered by blists - more mailing lists