From: "Bhatnagar, Rishabh" <risbhat@amazon.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>,
"sashal@kernel.org" <sashal@kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Herrenschmidt, Benjamin" <benh@amazon.com>,
"Bacco, Mike" <mbacco@amazon.com>
Subject: Re: [PATCH 0/6] IRQ handling patches backport to 4.14 stable
Date: Mon, 3 Oct 2022 17:54:35 +0000 [thread overview]
Message-ID: <9BEC548C-6849-483B-9A30-10EFFB145E1C@amazon.com> (raw)
In-Reply-To: <YzmujBxtwUxHexem@kroah.com>
On 10/2/22, 8:30 AM, "Greg KH" <gregkh@linuxfoundation.org> wrote:
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
On Thu, Sep 29, 2022 at 09:06:45PM +0000, Rishabh Bhatnagar wrote:
> This patch series backports a bunch of patches related IRQ handling
> with respect to freeing the irq line while IRQ is in flight at CPU
> or at the hardware level.
> Recently we saw this issue in serial 8250 driver where the IRQ was being
> freed while the irq was in flight or not yet delivered to the CPU. As a
> result the irqchip was going into a wedged state and IRQ was not getting
> delivered to the cpu. These patches helped fixed the issue in 4.14
> kernel.
Why is the serial driver freeing an irq while the system is running?
Ah, this could happen on a tty hangup, right?
Yes, exactly during tty hangup we see this sequence happening.
It doesn't happen on every hangup but can be reproduced within 10 tries. We didn't see the same
behavior in 5.10 and hence found these commits.
> Let us know if more patches need backporting.
What hardware platform were these patches tested on to verify they work
properly? And why can't they move to 4.19 or newer if they really need
this fix? What's preventing that?
As Amazon doesn't seem to be testing 4.14.y -rc releases, I find it odd
that you all did this backport. Is this a kernel that you all care
about?
These were tested on Intel x86_64 (Xeon Platinum 8259).
Amazon linux 2 still supports 4.14 kernel for our customers, so we would need to fix that.
thanks,
greg k-h
next prev parent reply other threads:[~2022-10-03 17:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-29 21:06 [PATCH 0/6] IRQ handling patches backport to 4.14 stable Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 1/6] genirq: Update code comments wrt recycled thread_mask Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 2/6] genirq: Synchronize only with single thread on free_irq() Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 3/6] genirq: Delay deactivation in free_irq() Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 4/6] genirq: Fix misleading synchronize_irq() documentation Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 5/6] genirq: Add optional hardware synchronization for shutdown Rishabh Bhatnagar
2022-09-29 21:06 ` [PATCH 6/6] x86/ioapic: Implement irq_get_irqchip_state() callback Rishabh Bhatnagar
2022-10-02 15:30 ` [PATCH 0/6] IRQ handling patches backport to 4.14 stable Greg KH
2022-10-03 17:54 ` Bhatnagar, Rishabh [this message]
2022-10-07 3:07 ` Herrenschmidt, Benjamin
2022-10-09 17:50 ` Bhatnagar, Rishabh
2022-10-14 19:00 ` Bhatnagar, Rishabh
2022-10-15 15:36 ` gregkh
2022-10-27 10:13 ` Greg KH
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=9BEC548C-6849-483B-9A30-10EFFB145E1C@amazon.com \
--to=risbhat@amazon.com \
--cc=benh@amazon.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mbacco@amazon.com \
--cc=mingo@redhat.com \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
/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.