Re: [PATCH v3 2/3] genirq: Always limit the affinity to online CPUs

From: Marc Zyngier <maz@kernel.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	'Linux Samsung SOC' <linux-samsung-soc@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	John Garry <john.garry@huawei.com>,
	Xiongfeng Wang <wangxiongfeng2@huawei.com>,
	David Decotigny <ddecotig@google.com>
Subject: Re: [PATCH v3 2/3] genirq: Always limit the affinity to online CPUs
Date: Wed, 20 Apr 2022 10:40:43 +0100	[thread overview]
Message-ID: <87mtgg9jok.wl-maz@kernel.org> (raw)
In-Reply-To: <70123e98-046f-f10e-1032-8d112edd3ecf@linaro.org>

Hi Krzysztof,

On Wed, 20 Apr 2022 10:13:52 +0100,
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
> On 14/04/2022 13:08, Marek Szyprowski wrote:
> >> Thanks for all of the debug, super helpful. The issue is that we don't
> >> handle the 'force' case, which a handful of drivers are using when
> >> bringing up CPUs (and doing so before the CPUs are marked online).
> >>
> >> Can you please give the below hack a go?
> > 
> > This patch fixed the issue. Thanks! Feel free to add my:
> > 
> > Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
> > 
> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> 
> Hi Marc,
> 
> Linux-next still fails to boot on Exynos5422 boards, so I wonder if you
> applied the fix?

It was picked up by Thomas and pushed out into tip, which is pulled by
-next:

maz@hot-poop:~/arm-platforms$ git describe --contains c48c8b829d2b966a6649827426bcdba082ccf922
next-20220420~51^2~3^2

So it definitely is in today's -next.

> Instead of silent fail there is now "Unable to handle kernel paging
> request at virtual address f0836644", so it is slightly different.
> 
> See the dmesg:
> https://krzk.eu/#/builders/21/builds/3542/steps/15/logs/serial0

This looks completely unrelated:

[   10.382010] Unable to handle kernel paging request at virtual address f0836644
[   10.388597] [f0836644] *pgd=41c83811, *pte=00000000, *ppte=00000000
[   10.394482] Internal error: Oops: 807 [#1] PREEMPT SMP ARM
[   10.399567] Modules linked in:
[   10.402583] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc3-next-20220420 #2
[   10.410060] Hardware name: Samsung Exynos (Flattened Device Tree)
[   10.416106] PC is at cpu_ca15_set_pte_ext+0x4c/0x58
[   10.420952] LR is at handle_pte_fault+0x218/0x260
[   10.425631] pc : [<c011d588>]    lr : [<c02ab188>]    psr: 40000113
[   10.431874] sp : f0835df0  ip : f0835e5c  fp : 00000081
[   10.437069] r10: c0f2eafc  r9 : c1d31000  r8 : 00000000
[   10.442268] r7 : c1d58000  r6 : 00000081  r5 : befffff6  r4 : f0835e24
[   10.448773] r3 : 00000000  r2 : 00000000  r1 : 00000040  r0 : f0835e44
[   10.455273] Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   10.462381] Control: 10c5387d  Table: 4000406a  DAC: 00000051

This is a crash in cpu_ca15_set_pte_ext() when populating the
userspace page tables, which seems unrelated to interrupt affinity.

I suggest you bisect this to find the actual problem.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.