All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thierry Reding <thierry.reding@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [RFC 1/2] core: Add generic object registry implementation
Date: Thu, 6 Nov 2014 17:13:24 +0100	[thread overview]
Message-ID: <20141106161321.GB14873@ulmo.nvidia.com> (raw)
In-Reply-To: <20141106102531.GI26297@ulmo>


[-- Attachment #1.1: Type: text/plain, Size: 1306 bytes --]

On Thu, Nov 06, 2014 at 11:25:32AM +0100, Thierry Reding wrote:
> On Wed, Nov 05, 2014 at 06:18:15PM -0800, Greg Kroah-Hartman wrote:
[...]
> > Sure, document it better if you want, but I think something needs to be
> > done differently if at all possible.
> 
> try_module_get() is the only way I know of that ensures that the code of
> a module stays around. Everytime we give out a new reference to a record
> we also need to increment the module reference count accordingly to make
> sure the underlying code doesn't go away all of a sudden.
> 
> I guess that's not entirely accurate. The module reference count doesn't
> have to be increment for every record reference, it only needs to track
> each record. So the try_module_get() and module_put() could move into
> registry_add() and registry_get(), respectively. But the ->owner field
> would still be in the record structure.

On further thought I don't think this will work either. Given that the
record can be removed from the registry while somebody else still has a
reference to it, the module owning the record must stay around as long
as there's a reference to the record.

Maybe the module reference count needs to be incremented when the record
is initialized and decremented when the record is released.

Thierry

[-- Attachment #1.2: Type: application/pgp-signature, Size: 819 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

WARNING: multiple messages have this Message-ID (diff)
From: Thierry Reding <thierry.reding@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	David Herrmann <dh.herrmann@gmail.com>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC 1/2] core: Add generic object registry implementation
Date: Thu, 6 Nov 2014 17:13:24 +0100	[thread overview]
Message-ID: <20141106161321.GB14873@ulmo.nvidia.com> (raw)
In-Reply-To: <20141106102531.GI26297@ulmo>

[-- Attachment #1: Type: text/plain, Size: 1306 bytes --]

On Thu, Nov 06, 2014 at 11:25:32AM +0100, Thierry Reding wrote:
> On Wed, Nov 05, 2014 at 06:18:15PM -0800, Greg Kroah-Hartman wrote:
[...]
> > Sure, document it better if you want, but I think something needs to be
> > done differently if at all possible.
> 
> try_module_get() is the only way I know of that ensures that the code of
> a module stays around. Everytime we give out a new reference to a record
> we also need to increment the module reference count accordingly to make
> sure the underlying code doesn't go away all of a sudden.
> 
> I guess that's not entirely accurate. The module reference count doesn't
> have to be increment for every record reference, it only needs to track
> each record. So the try_module_get() and module_put() could move into
> registry_add() and registry_get(), respectively. But the ->owner field
> would still be in the record structure.

On further thought I don't think this will work either. Given that the
record can be removed from the registry while somebody else still has a
reference to it, the module owning the record must stay around as long
as there's a reference to the record.

Maybe the module reference count needs to be incremented when the record
is initialized and decremented when the record is released.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

  reply	other threads:[~2014-11-06 16:13 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-04 16:29 [RFC 1/2] core: Add generic object registry implementation Thierry Reding
2014-11-04 16:29 ` Thierry Reding
2014-11-04 16:29 ` [RFC 2/2] drm/panel: Use generic object registry Thierry Reding
2014-11-04 16:29   ` Thierry Reding
2014-11-04 16:38 ` [RFC 1/2] core: Add generic object registry implementation Greg Kroah-Hartman
2014-11-04 16:38   ` Greg Kroah-Hartman
2014-11-05  9:13   ` Thierry Reding
2014-11-05  9:13     ` Thierry Reding
2014-11-06  2:18     ` Greg Kroah-Hartman
2014-11-06  2:18       ` Greg Kroah-Hartman
2014-11-06 10:25       ` Thierry Reding
2014-11-06 10:25         ` Thierry Reding
2014-11-06 16:13         ` Thierry Reding [this message]
2014-11-06 16:13           ` Thierry Reding
2014-11-07 16:31           ` Greg Kroah-Hartman
2014-11-07 16:31             ` Greg Kroah-Hartman
2014-11-05 12:36 ` Andrzej Hajda
2014-11-05 12:36   ` Andrzej Hajda
2014-11-05 14:04   ` Thierry Reding
2014-11-05 14:04     ` Thierry Reding
2014-11-05 16:00     ` Andrzej Hajda
2014-11-05 16:00       ` Andrzej Hajda
2014-11-06  9:48       ` Thierry Reding
2014-11-06  9:48         ` Thierry Reding
2014-11-07  9:10         ` Andrzej Hajda
2014-11-07  9:10           ` Andrzej Hajda

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=20141106161321.GB14873@ulmo.nvidia.com \
    --to=thierry.reding@gmail.com \
    --cc=daniel.vetter@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.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 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.