Messages in this thread | | | Date | Mon, 05 Jul 2021 19:01:38 +0100 | From | Marc Zyngier <> | Subject | Re: [irqchip: irq/irqchip-next] irqdomain: Protect the linear revmap with RCU |
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Hi Guenter,
On Mon, 05 Jul 2021 18:23:52 +0100, Guenter Roeck <linux@roeck-us.net> wrote: > > Hi, > > On Fri, Jun 11, 2021 at 01:54:36PM -0000, irqchip-bot for Marc Zyngier wrote: > > The following commit has been merged into the irq/irqchip-next branch of irqchip: > > > > Commit-ID: d4a45c68dc81f9117ceaff9f058d5fae674181b9 > > Gitweb: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/d4a45c68dc81f9117ceaff9f058d5fae674181b9 > > Author: Marc Zyngier <maz@kernel.org> > > AuthorDate: Mon, 05 Apr 2021 12:57:27 +01:00 > > Committer: Marc Zyngier <maz@kernel.org> > > CommitterDate: Thu, 10 Jun 2021 13:09:18 +01:00 > > > > irqdomain: Protect the linear revmap with RCU > > > > It is pretty odd that the radix tree uses RCU while the linear > > portion doesn't, leading to potential surprises for the users, > > depending on how the irqdomain has been created. > > > > Fix this by moving the update of the linear revmap under > > the mutex, and the lookup under the RCU read-side lock. > > > > The mutex name is updated to reflect that it doesn't only > > cover the radix-tree anymore. > > > > Signed-off-by: Marc Zyngier <maz@kernel.org> > > This patch results in various RCU warnings when booting mipsel images > in qemu. I can not revert the patch due to subsequent changes, so I > don't know if a simple revert fixes the problem. Log messages and > bisect log see below.
Thanks for the heads up. Do you have a config file I can use to reproduce this? The QEMU invocation runes would certainly help too.
It strikes me that in drivers/irqchip/irq-mips-cpu.c, plat_irq_dispatch() now uses the irqdomain resolution before irq_enter() took place. That's certainly a latent bug. I'll fix that regardless, but I'd like to make sure this is what you are seeing too.
Thanks,
M.
-- Without deviation from the norm, progress is not possible.
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