From mboxrd@z Thu Jan  1 00:00:00 1970
From: Valentin Schneider <vschneid@redhat.com>
Subject: Re: [RFC PATCH 4/5] irq_work: Trace calls to arch_irq_work_raise()
Date: Tue, 11 Oct 2022 16:02:06 +0100
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To: Steven Rostedt <rostedt@goodmis.org>
Cc: Juri Lelli <juri.lelli@redhat.com>, Mark Rutland <mark.rutland@arm.com>, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, Dave Hansen <dave.hansen@linux.intel.com>, linux-mips@vger.kernel.org, Guo Ren <guoren@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Marc Zyngier <maz@kernel.org>, linux-hexagon@vger.kernel.org, x86@kernel.org, Russell King <linux@armlinux.org.uk>, linux-csky@vger.kernel.org, Ingo Molnar <mingo@redhat.com>, linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, "Paul E. McKenney" <paulmck@kernel.org>, Frederic Weisbecker <frederic@kernel.org>, Nicholas Piggin <npiggin@gmai>, l.com, , openrisc@lists.librecores.org, Borislav Petkov <bp@alien8.de>, loongarch@lists.linux.dev

On 08/10/22 15:34, Steven Rostedt wrote:
> On Fri,  7 Oct 2022 16:45:32 +0100
> Valentin Schneider <vschneid@redhat.com> wrote:
>>  }
>>  
>> +static inline void irq_work_raise(void)
>> +{
>> +	if (arch_irq_work_has_interrupt())
>> +		trace_ipi_send_cpu(_RET_IP_, smp_processor_id());
>
> To save on the branch, let's make the above:
>
> 	if (trace_ipi_send_cpu_enabled() && arch_irq_work_has_interrupt())
>
> As the "trace_*_enabled()" is a static branch that will make it a nop
> when the tracepoint is not enabled.
>

Makes sense, thanks for the suggestion.

> -- Steve
>
>
>> +
>> +	arch_irq_work_raise();
>> +}
>> +
>>  /* Enqueue on current CPU, work must already be claimed and preempt disabled */