All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Gregor Dick <gdick-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
	Kieran Mansley <kmansley-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
Subject: Re: PROBLEM: Deadlock in attach_device() in AMD IOMMU driver
Date: Tue, 5 May 2015 17:33:44 +0200	[thread overview]
Message-ID: <20150505153344.GR15736@8bytes.org> (raw)
In-Reply-To: <5548D814.6020807-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>

On Tue, May 05, 2015 at 03:47:48PM +0100, Gregor Dick wrote:
> Hi Joerg,
> 
> On 05/05/15 15:41, Joerg Roedel wrote:
> >Do you see a real deadlock or only the lockdep warning? In the code it
> >looks like virtfn_add() takes the sriov->lock of the physical device
> >while pci_enable_ats() (when called from there) takes the sriov->lock of
> >the virtual function. In this case it couldn't deadlock.
> 
> The thread does deadlock. It looks like pci_enable_ats() takes
> dev->physfn->sriov->lock, where dev is the VF. I'd understood this to be
> a lock protecting SR-IOV state for all VFs configured on the PF (but I'm
> not familiar with the code at all!).

Okay, I'll have a look into the SLES12 kernel sources to check there.
Can you reproduce this with a recent upstream kernel?


	Joerg

  parent reply	other threads:[~2015-05-05 15:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-05  9:24 PROBLEM: Deadlock in attach_device() in AMD IOMMU driver Gregor Dick
     [not found] ` <55488C3D.50509-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2015-05-05 14:41   ` Joerg Roedel
     [not found]     ` <20150505144159.GI15736-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2015-05-05 14:47       ` Gregor Dick
     [not found]         ` <5548D814.6020807-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2015-05-05 15:33           ` Joerg Roedel [this message]
     [not found]             ` <20150505153344.GR15736-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2015-05-06 11:44               ` Gregor Dick
     [not found]                 ` <5549FEA1.9080801-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>
2015-05-11 10:15                   ` Joerg Roedel

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=20150505153344.GR15736@8bytes.org \
    --to=joro-zlv9swrftaidnm+yrofe0a@public.gmane.org \
    --cc=gdick-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org \
    --cc=iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org \
    --cc=kmansley-s/n/eUQHGBpZroRs9YW3xA@public.gmane.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 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.