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From: Sumit Garg <sumit.garg@linaro.org>
To: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	Mark Rutland <mark.rutland@arm.com>,
	julien.thierry.kdev@gmail.com,
	Douglas Anderson <dianders@chromium.org>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jason Wessel <jason.wessel@windriver.com>,
	Masayoshi Mizuma <msys.mizuma@gmail.com>,
	ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI
Date: Tue, 20 Oct 2020 12:37:24 +0530	[thread overview]
Message-ID: <CAFA6WYN18oe9143offQ1V5RwnYZmvy29vPR0SKFtpkdOePezsQ@mail.gmail.com> (raw)
In-Reply-To: <b366c68fe0b365892aa4324be90235d6@kernel.org>

On Mon, 19 Oct 2020 at 17:26, Marc Zyngier <maz@kernel.org> wrote:
>
> On 2020-10-14 12:12, Sumit Garg wrote:
> > Introduce framework to turn an IPI as NMI using pseudo NMIs. In case a
> > particular platform doesn't support pseudo NMIs, then request IPI as a
> > regular IRQ.
> >
> > The main motivation for this feature is to have an IPI that can be
> > leveraged to invoke NMI functions on other CPUs. And current
> > prospective
> > users are NMI backtrace and KGDB CPUs round-up whose support is added
> > via future patches.
> >
> > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> > ---
> >  arch/arm64/include/asm/nmi.h | 16 +++++++++
> >  arch/arm64/kernel/Makefile   |  2 +-
> >  arch/arm64/kernel/ipi_nmi.c  | 77
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 94 insertions(+), 1 deletion(-)
> >  create mode 100644 arch/arm64/include/asm/nmi.h
> >  create mode 100644 arch/arm64/kernel/ipi_nmi.c
>
> [...]
>
> > +     irq_set_status_flags(ipi, IRQ_HIDDEN);
>
> Another thing is this. Why are you hiding this from /proc/interrupts?
> The only reason the other IPIs are hidden is that displaying them as
> "normal" interrupts would be a change in userspace ABI.
>
> In your case, this is something new that can perfectly appear as
> a standard interrupt (and I don't see how you'd display the
> statistics otherwise).

Makes sense. I will remove this flag for this IPI so that it can be
displayed as a standard interrupt.

-Sumit

>
>          M.
> --
> Jazz is not dead. It just smells funny...

  reply	other threads:[~2020-10-20  7:07 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-14 11:12 [PATCH v5 0/5] arm64: Add framework to turn an IPI as NMI Sumit Garg
2020-10-14 11:12 ` [PATCH v5 1/5] arm64: Add framework to turn " Sumit Garg
2020-10-15  1:15   ` Masayoshi Mizuma
2020-10-19 11:37   ` Marc Zyngier
2020-10-20  6:43     ` Sumit Garg
2020-10-20 10:08       ` Marc Zyngier
2020-10-20 11:22         ` Sumit Garg
2020-10-20 12:25           ` Daniel Thompson
2020-10-20 12:32             ` Marc Zyngier
2020-10-21  5:22               ` Sumit Garg
2020-10-21 10:27           ` Marc Zyngier
2020-10-22 11:52             ` Sumit Garg
2020-10-19 11:56   ` Marc Zyngier
2020-10-20  7:07     ` Sumit Garg [this message]
2020-10-14 11:12 ` [PATCH v5 2/5] irqchip/gic-v3: Enable support for SGIs to act as NMIs Sumit Garg
2020-10-15  1:16   ` Masayoshi Mizuma
2020-10-19 12:07   ` Marc Zyngier
2020-10-20  7:24     ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 3/5] arm64: smp: Allocate and setup IPI as NMI Sumit Garg
2020-10-15  1:16   ` Masayoshi Mizuma
2020-10-19 11:59   ` Marc Zyngier
2020-10-20  7:16     ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 4/5] arm64: kgdb: Round up cpus using " Sumit Garg
2020-10-19 12:15   ` Marc Zyngier
2020-10-20  8:51     ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 5/5] arm64: ipi_nmi: Add support for NMI backtrace Sumit Garg
2020-10-15  1:17   ` Masayoshi Mizuma
2020-10-19 12:20   ` Marc Zyngier
2020-10-20  9:13     ` Sumit Garg
2020-10-21 10:32       ` Marc Zyngier
2020-10-21 11:28         ` Sumit Garg

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