From: Marc Zyngier <maz@kernel.org>
To: Valentin Schneider <valentin.schneider@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Russell King <linux@arm.linux.org.uk>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>,
Sumit Garg <sumit.garg@linaro.org>,
Florian Fainelli <f.fainelli@gmail.com>,
Gregory Clement <gregory.clement@bootlin.com>,
Andrew Lunn <andrew@lunn.ch>,
kernel-team@android.com
Subject: Re: [PATCH v2 15/17] arm64: Remove custom IRQ stat accounting
Date: Sat, 27 Jun 2020 12:42:52 +0100 [thread overview]
Message-ID: <2f41d622f1f9e41026e93c2dc18aa65b@kernel.org> (raw)
In-Reply-To: <jhjd05lh10j.mognet@arm.com>
On 2020-06-27 00:15, Valentin Schneider wrote:
> On 26/06/20 12:58, Marc Zyngier wrote:
>> On 2020-06-25 19:26, Valentin Schneider wrote:
>>> On 24/06/20 20:58, Marc Zyngier wrote:
>>>> @@ -801,26 +802,15 @@ void show_ipi_list(struct seq_file *p, int
>>>> prec)
>>>> unsigned int cpu, i;
>>>>
>>>> for (i = 0; i < NR_IPI; i++) {
>>>> + unsigned int irq = irq_desc_get_irq(ipi_desc[i]);
>>>> seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
>>>> prec >= 4 ? " " : "");
>>>> for_each_online_cpu(cpu)
>>>> - seq_printf(p, "%10u ",
>>>> - __get_irq_stat(cpu, ipi_irqs[i]));
>>>> + seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
>>>> seq_printf(p, " %s\n", ipi_types[i]);
>>>
>>> How attached are we to that custom IPI printout? AIUI we *could* give
>>> them
>>> a "prettier" name in request_percpu_irq() and let the standard procfs
>>> printout take the wheel.
>>
>> I wish. Unfortunately, /proc/interrupts is likely to be considered
>> ABI,
>> and I'm really worried to change this (see what happened last time we
>> tried to update /proc/cpuinfo to be less braindead...).
>>
>
> Hmph, it's borderline here I think: we're not introducing a new field
> or
> format in the file, so any tool that can parse /proc/interrupts can
> parse
> the IPIs if they are formatted like the other "regular" interrupts. But
> then said tool could die in flames when not seeing the special IPI
> fields
> because sturdiness is overrated :(
Which is exactly what I'm worried about. People do stupid things,
and stupidity becomes ABI. I hate luserspace.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-06-27 11:42 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-24 19:57 [PATCH v2 00/17] arm/arm64: Turning IPIs into normal interrupts Marc Zyngier
2020-06-24 19:57 ` [PATCH v2 01/17] genirq: Add fasteoi IPI flow Marc Zyngier
2020-06-24 19:57 ` [PATCH v2 02/17] genirq: Allow interrupts to be excluded from /proc/interrupts Marc Zyngier
2020-06-24 19:57 ` [PATCH v2 03/17] arm64: Allow IPIs to be handled as normal interrupts Marc Zyngier
2020-06-25 18:25 ` Valentin Schneider
2020-07-10 19:58 ` Valentin Schneider
2020-06-24 19:57 ` [PATCH v2 04/17] ARM: " Marc Zyngier
2020-06-25 18:25 ` Valentin Schneider
2020-06-29 9:37 ` Marc Zyngier
2020-06-24 19:57 ` [PATCH v2 05/17] irqchip/gic-v3: Describe the SGI range Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 06/17] irqchip/gic-v3: Configure SGIs as standard interrupts Marc Zyngier
2020-06-25 18:25 ` Valentin Schneider
2020-06-30 10:15 ` Marc Zyngier
2020-07-02 13:23 ` Valentin Schneider
2020-07-02 13:48 ` Marc Zyngier
2020-07-02 14:24 ` Valentin Schneider
2020-06-24 19:58 ` [PATCH v2 07/17] irqchip/gic: Atomically update affinity Marc Zyngier
2020-07-01 19:33 ` Sasha Levin
2020-07-10 14:02 ` Sasha Levin
2021-09-09 15:22 ` Geert Uytterhoeven
2021-09-09 15:37 ` Russell King (Oracle)
2021-09-10 10:22 ` Marc Zyngier
2021-09-10 13:19 ` Geert Uytterhoeven
2021-09-11 2:49 ` Magnus Damm
2021-09-11 19:32 ` Marc Zyngier
2021-09-12 5:40 ` Magnus Damm
2021-09-13 8:05 ` Geert Uytterhoeven
2021-09-15 3:28 ` Magnus Damm
2021-09-22 13:53 ` [irqchip: irq/irqchip-fixes] irqchip/gic: Work around broken Renesas integration irqchip-bot for Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 08/17] irqchip/gic: Refactor SMP configuration Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 09/17] irqchip/gic: Configure SGIs as standard interrupts Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 10/17] irqchip/gic-common: Don't enable SGIs by default Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 11/17] irqchip/bcm2836: Configure mailbox interrupts as standard interrupts Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 12/17] irqchip/hip04: Configure IPIs " Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 13/17] irqchip/armada-370-xp: " Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 14/17] arm64: Kill __smp_cross_call and co Marc Zyngier
2020-06-25 18:25 ` Valentin Schneider
2020-07-02 13:37 ` Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 15/17] arm64: Remove custom IRQ stat accounting Marc Zyngier
2020-06-25 18:26 ` Valentin Schneider
2020-06-26 11:58 ` Marc Zyngier
2020-06-26 23:15 ` Valentin Schneider
2020-06-27 11:42 ` Marc Zyngier [this message]
2020-07-10 19:58 ` Valentin Schneider
2020-06-24 19:58 ` [PATCH v2 16/17] ARM: Kill __smp_cross_call and co Marc Zyngier
2020-06-24 19:58 ` [PATCH v2 17/17] ARM: Remove custom IRQ stat accounting Marc Zyngier
2020-06-25 18:24 ` [PATCH v2 00/17] arm/arm64: Turning IPIs into normal interrupts Valentin Schneider
2020-07-10 19:58 ` Valentin Schneider
2020-08-11 13:15 ` Sumit Garg
2020-08-11 13:58 ` Marc Zyngier
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=2f41d622f1f9e41026e93c2dc18aa65b@kernel.org \
--to=maz@kernel.org \
--cc=andrew@lunn.ch \
--cc=catalin.marinas@arm.com \
--cc=f.fainelli@gmail.com \
--cc=gregory.clement@bootlin.com \
--cc=jason@lakedaemon.net \
--cc=kernel-team@android.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=sumit.garg@linaro.org \
--cc=tglx@linutronix.de \
--cc=valentin.schneider@arm.com \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).