From: Marc Zyngier <maz@kernel.org>
To: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Sumit Garg <sumit.garg@linaro.org>,
Jason Cooper <jason@lakedaemon.net>,
Catalin Marinas <catalin.marinas@arm.com>,
ito-yuichi@fujitsu.com, Douglas Anderson <dianders@chromium.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
julien.thierry.kdev@gmail.com,
Jason Wessel <jason.wessel@windriver.com>,
kgdb-bugreport@lists.sourceforge.net,
Thomas Gleixner <tglx@linutronix.de>,
Masayoshi Mizuma <msys.mizuma@gmail.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI
Date: Tue, 20 Oct 2020 13:32:03 +0100 [thread overview]
Message-ID: <abe358694e06a6076fb5838d1231eee6@kernel.org> (raw)
In-Reply-To: <20201020122535.paym32gksuhcqtwq@holly.lan>
On 2020-10-20 13:25, Daniel Thompson wrote:
> On Tue, Oct 20, 2020 at 04:52:43PM +0530, Sumit Garg wrote:
[...]
>> So in general, IPI as a normal IRQ is still useful for debugging but
>> it can't debug a core which is stuck in deadlock with interrupts
>> disabled.
>>
>> And since we choose override default implementations for pseudo NMI
>> support, we need to be backwards compatible for platforms which don't
>> possess pseudo NMI support.
>
> Do the fallback implementations require a new IPI? The fallbacks
> could rely on existing mechanisms such as the smp_call_function
> family.
Indeed. I'd be worried of using that mechanism for NMIs, but normal
IPIs should stick to the normal cross-call stuff.
The jury is still out on why this is a good idea, given that it
doesn't work in the only interesting case (deadlocked CPUs).
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sumit Garg <sumit.garg@linaro.org>,
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>,
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 13:32:03 +0100 [thread overview]
Message-ID: <abe358694e06a6076fb5838d1231eee6@kernel.org> (raw)
In-Reply-To: <20201020122535.paym32gksuhcqtwq@holly.lan>
On 2020-10-20 13:25, Daniel Thompson wrote:
> On Tue, Oct 20, 2020 at 04:52:43PM +0530, Sumit Garg wrote:
[...]
>> So in general, IPI as a normal IRQ is still useful for debugging but
>> it can't debug a core which is stuck in deadlock with interrupts
>> disabled.
>>
>> And since we choose override default implementations for pseudo NMI
>> support, we need to be backwards compatible for platforms which don't
>> possess pseudo NMI support.
>
> Do the fallback implementations require a new IPI? The fallbacks
> could rely on existing mechanisms such as the smp_call_function
> family.
Indeed. I'd be worried of using that mechanism for NMIs, but normal
IPIs should stick to the normal cross-call stuff.
The jury is still out on why this is a good idea, given that it
doesn't work in the only interesting case (deadlocked CPUs).
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-10-20 12:33 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 [this message]
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
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=abe358694e06a6076fb5838d1231eee6@kernel.org \
--to=maz@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=daniel.thompson@linaro.org \
--cc=dianders@chromium.org \
--cc=ito-yuichi@fujitsu.com \
--cc=jason.wessel@windriver.com \
--cc=jason@lakedaemon.net \
--cc=julien.thierry.kdev@gmail.com \
--cc=kgdb-bugreport@lists.sourceforge.net \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=msys.mizuma@gmail.com \
--cc=sumit.garg@linaro.org \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.