Re: [patch 02/19] sh: Get rid of nmi_count()

From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
To: Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Paul McKenney <paulmck@kernel.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Arnd Bergmann <arnd@arndb.de>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Rich Felker <dalias@libc.org>,
	linux-sh@vger.kernel.org,
	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	Helge Deller <deller@gmx.de>,
	linux-parisc@vger.kernel.org, Jeff Dike <jdike@addtoit.com>,
	Richard Weinberger <richard@nod.at>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	linux-um@lists.infradead.org,
	Russell King <linux@armlinux.org.uk>,
	Marc Zyngier <maz@kernel.org>,
	Valentin Schneider <valentin.schneider@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Subject: Re: [patch 02/19] sh: Get rid of nmi_count()
Date: Fri, 1 Jan 2021 15:27:57 +0100	[thread overview]
Message-ID: <b9275f62-45c2-2472-2c1d-00706c757a30@physik.fu-berlin.de> (raw)
In-Reply-To: <20201113141732.844232404@linutronix.de>

Hello Thomas!

On 11/13/20 3:02 PM, Thomas Gleixner wrote:
> nmi_count() is a historical leftover and SH is the only user. Replace it
> with regular per cpu accessors.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Cc: Rich Felker <dalias@libc.org>
> Cc: linux-sh@vger.kernel.org
> ---
>  arch/sh/kernel/irq.c   |    2 +-
>  arch/sh/kernel/traps.c |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> --- a/arch/sh/kernel/irq.c
> +++ b/arch/sh/kernel/irq.c
> @@ -44,7 +44,7 @@ int arch_show_interrupts(struct seq_file
>  
>  	seq_printf(p, "%*s: ", prec, "NMI");
>  	for_each_online_cpu(j)
> -		seq_printf(p, "%10u ", nmi_count(j));
> +		seq_printf(p, "%10u ", per_cpu(irq_stat.__nmi_count, j);
>  	seq_printf(p, "  Non-maskable interrupts\n");
>  
>  	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
> --- a/arch/sh/kernel/traps.c
> +++ b/arch/sh/kernel/traps.c
> @@ -186,7 +186,7 @@ BUILD_TRAP_HANDLER(nmi)
>  	arch_ftrace_nmi_enter();
>  
>  	nmi_enter();
> -	nmi_count(cpu)++;
> +	this_cpu_inc(irq_stat.__nmi_count);
>  
>  	switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
>  	case NOTIFY_OK:
> 

Just booted my SH7785LCR board with a kernel based on Linus' latest tree
and can confirm that this change does not cause any regressions.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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