linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: "Raj\, Ashok" <ashok.raj@intel.com>
Cc: "Raj\, Ashok" <ashok.raj@linux.intel.com>,
	Evan Green <evgreen@chromium.org>,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	x86@kernel.org, linux-pci <linux-pci@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>, "Ghorai\,
	Sukumar" <sukumar.ghorai@intel.com>, "Amara\,
	Madhusudanarao" <madhusudanarao.amara@intel.com>, "Nandamuri\,
	Srikanth" <srikanth.nandamuri@intel.com>,
	Ashok Raj <ashok.raj@intel.com>
Subject: Re: MSI interrupt for xhci still lost on 5.6-rc6 after cpu hotplug
Date: Thu, 07 May 2020 21:41:36 +0200	[thread overview]
Message-ID: <87blmzedn3.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200507175715.GA22426@otc-nc-03>

Ashok,

"Raj, Ashok" <ashok.raj@intel.com> writes:
> 
> I think i got mixed up with logical apic id and logical cpu :-(

Stuff happens.

>           <idle>-0     [000] d.h.    44.376659: msi_set_affinity: quirk[1] new vector allocated, new apic = 2 vector = 33 this apic = 0
>           <idle>-0     [000] d.h.    44.376684: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 0 Nvec 33 Napic 2

>           <idle>-0     [000] d.h.    44.376685: xhci_irq: xhci irq

>           <idle>-0     [001] d.h.    44.376750: msi_set_affinity: quirk[1] new vector allocated, new apic = 2 vector = 33 this apic = 2
>           <idle>-0     [001] d.h.    44.376774: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 2 Nvec 33 Napic 2

>           <idle>-0     [001] d.h.    44.376776: xhci_irq: xhci irq
>           <idle>-0     [001] d.h.    44.395824: xhci_irq: xhci irq

>            <...>-14    [001] d..1    44.400666: msi_set_affinity: quirk[1] new vector allocated, new apic = 6 vector = 33 this apic = 2
>            <...>-14    [001] d..1    44.400691: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 2 Nvec 33 Napic 6

>           <idle>-0     [003] d.h.    44.421021: xhci_irq: xhci irq
>           <idle>-0     [003] d.h.    44.421135: xhci_irq: xhci irq

>      migration/3-24    [003] d..1    44.421784: msi_set_affinity: quirk[1] new vector allocated, new apic = 0 vector = 33 this apic = 6
>      migration/3-24    [003] d..1    44.421803: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 6 Nvec 33 Napic 0

So this last one is a direct update. Straight forward moving it from one
to the other CPU on the same vector number.

And that's the case where we either expect the interrupt to come in on
CPU3 or on CPU0.

There is actually an example in the trace:

	<idle>-0     [000] d.h.    40.616467: msi_set_affinity: quirk[1] new vector allocated, new apic = 2 vector = 33 this apic = 0
	<idle>-0     [000] d.h.    40.616488: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 0 Nvec 33 Napic 2
	<idle>-0     [000] d.h.    40.616488: xhci_irq: xhci irq
	<idle>-0     [001] d.h.    40.616504: xhci_irq: xhci irq

>      migration/3-24    [003] d..1    44.421784: msi_set_affinity: quirk[1] new vector allocated, new apic = 0 vector = 33 this apic = 6
>      migration/3-24    [003] d..1    44.421803: msi_set_affinity: Direct Update: irq 123 Ovec=33 Oapic 6 Nvec 33 Napic 0

But as this last one is the migration thread, aka stomp machine, I
assume this is a hotplug operation. Which means the CPU cannot handle
interrupts anymore. In that case we check the old vector on the
unplugged CPU in fixup_irqs() and do the retrigger from there.
Can you please add tracing to that one as well?

Thanks,

        tglx





  parent reply	other threads:[~2020-05-07 19:41 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-18 19:25 MSI interrupt for xhci still lost on 5.6-rc6 after cpu hotplug Mathias Nyman
2020-03-19 20:24 ` Evan Green
2020-03-20  8:07   ` Mathias Nyman
2020-03-20  9:52 ` Thomas Gleixner
2020-03-23  9:42   ` Mathias Nyman
2020-03-23 14:10     ` Thomas Gleixner
2020-03-23 20:32       ` Mathias Nyman
2020-03-24  0:24         ` Thomas Gleixner
2020-03-24 16:17           ` Evan Green
2020-03-24 19:03             ` Thomas Gleixner
2020-05-01 18:43               ` Raj, Ashok
2020-05-05 19:36                 ` Thomas Gleixner
2020-05-05 20:16                   ` Raj, Ashok
2020-05-05 21:47                     ` Thomas Gleixner
2020-05-07 12:18                       ` Raj, Ashok
2020-05-07 12:53                         ` Thomas Gleixner
     [not found]                           ` <20200507175715.GA22426@otc-nc-03>
2020-05-07 19:41                             ` Thomas Gleixner [this message]
2020-03-25 17:12             ` Mathias Nyman
     [not found] <20200508005528.GB61703@otc-nc-03>
2020-05-08 11:04 ` Thomas Gleixner
2020-05-08 16:09   ` Raj, Ashok
2020-05-08 16:49     ` Thomas Gleixner
2020-05-11 19:03       ` Raj, Ashok
2020-05-11 20:14         ` Thomas Gleixner

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=87blmzedn3.fsf@nanos.tec.linutronix.de \
    --to=tglx@linutronix.de \
    --cc=ashok.raj@intel.com \
    --cc=ashok.raj@linux.intel.com \
    --cc=bhelgaas@google.com \
    --cc=evgreen@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=madhusudanarao.amara@intel.com \
    --cc=mathias.nyman@linux.intel.com \
    --cc=srikanth.nandamuri@intel.com \
    --cc=sukumar.ghorai@intel.com \
    --cc=x86@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).