From: Marc Zyngier <maz@kernel.org>
To: Sumit Garg <sumit.garg@linaro.org>
Cc: mark.rutland@arm.com, daniel.thompson@linaro.org,
jason@lakedaemon.net, catalin.marinas@arm.com,
ito-yuichi@fujitsu.com, dianders@chromium.org,
linux-kernel@vger.kernel.org, julien.thierry.kdev@gmail.com,
jason.wessel@windriver.com, kgdb-bugreport@lists.sourceforge.net,
tglx@linutronix.de, msys.mizuma@gmail.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI
Date: Mon, 19 Oct 2020 12:56:25 +0100 [thread overview]
Message-ID: <b366c68fe0b365892aa4324be90235d6@kernel.org> (raw)
In-Reply-To: <1602673931-28782-2-git-send-email-sumit.garg@linaro.org>
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).
M.
--
Jazz is not dead. It just smells funny...
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WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Sumit Garg <sumit.garg@linaro.org>
Cc: catalin.marinas@arm.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org, tglx@linutronix.de,
jason@lakedaemon.net, mark.rutland@arm.com,
julien.thierry.kdev@gmail.com, dianders@chromium.org,
daniel.thompson@linaro.org, jason.wessel@windriver.com,
msys.mizuma@gmail.com, ito-yuichi@fujitsu.com,
kgdb-bugreport@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI
Date: Mon, 19 Oct 2020 12:56:25 +0100 [thread overview]
Message-ID: <b366c68fe0b365892aa4324be90235d6@kernel.org> (raw)
In-Reply-To: <1602673931-28782-2-git-send-email-sumit.garg@linaro.org>
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).
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-10-19 11:57 UTC|newest]
Thread overview: 62+ 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 ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 1/5] arm64: Add framework to turn " Sumit Garg
2020-10-14 11:12 ` Sumit Garg
2020-10-15 1:15 ` Masayoshi Mizuma
2020-10-15 1:15 ` Masayoshi Mizuma
2020-10-19 11:37 ` Marc Zyngier
2020-10-19 11:37 ` Marc Zyngier
2020-10-20 6:43 ` Sumit Garg
2020-10-20 6:43 ` Sumit Garg
2020-10-20 10:08 ` Marc Zyngier
2020-10-20 10:08 ` Marc Zyngier
2020-10-20 11:22 ` Sumit Garg
2020-10-20 11:22 ` Sumit Garg
2020-10-20 12:25 ` Daniel Thompson
2020-10-20 12:25 ` Daniel Thompson
2020-10-20 12:32 ` Marc Zyngier
2020-10-20 12:32 ` Marc Zyngier
2020-10-21 5:22 ` Sumit Garg
2020-10-21 5:22 ` Sumit Garg
2020-10-21 10:27 ` Marc Zyngier
2020-10-21 10:27 ` Marc Zyngier
2020-10-22 11:52 ` Sumit Garg
2020-10-22 11:52 ` Sumit Garg
2020-10-19 11:56 ` Marc Zyngier [this message]
2020-10-19 11:56 ` Marc Zyngier
2020-10-20 7:07 ` Sumit Garg
2020-10-20 7:07 ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 2/5] irqchip/gic-v3: Enable support for SGIs to act as NMIs Sumit Garg
2020-10-14 11:12 ` Sumit Garg
2020-10-15 1:16 ` Masayoshi Mizuma
2020-10-15 1:16 ` Masayoshi Mizuma
2020-10-19 12:07 ` Marc Zyngier
2020-10-19 12:07 ` Marc Zyngier
2020-10-20 7:24 ` Sumit Garg
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
2020-10-14 11:12 ` Sumit Garg
2020-10-15 1:16 ` Masayoshi Mizuma
2020-10-15 1:16 ` Masayoshi Mizuma
2020-10-19 11:59 ` Marc Zyngier
2020-10-19 11:59 ` Marc Zyngier
2020-10-20 7:16 ` Sumit Garg
2020-10-20 7:16 ` Sumit Garg
2020-10-14 11:12 ` [PATCH v5 4/5] arm64: kgdb: Round up cpus using " Sumit Garg
2020-10-14 11:12 ` Sumit Garg
2020-10-19 12:15 ` Marc Zyngier
2020-10-19 12:15 ` Marc Zyngier
2020-10-20 8:51 ` Sumit Garg
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
2020-10-14 11:12 ` Sumit Garg
2020-10-15 1:17 ` Masayoshi Mizuma
2020-10-15 1:17 ` Masayoshi Mizuma
2020-10-19 12:20 ` Marc Zyngier
2020-10-19 12:20 ` Marc Zyngier
2020-10-20 9:13 ` Sumit Garg
2020-10-20 9:13 ` Sumit Garg
2020-10-21 10:32 ` Marc Zyngier
2020-10-21 10:32 ` Marc Zyngier
2020-10-21 11:28 ` Sumit Garg
2020-10-21 11:28 ` Sumit Garg
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