Re: Your gdm changes and SunRay...

[Jens Langner]

Hi,

as Brian Cameron asked me to continue the discussion on the gdm mailing
list I am sending my replay about the latest MultiSeat changes in gdm
here now.

As an introduction: We are currently trying to get the latest SunRay
Server (SRS) 4.2 version running with Ubuntu 9.10 which in turn uses gdm
2.28. However, as SRS is heavily relying on the previous "gdmdynamic"
feature the SRS software is not working out-of-the-box anymore with
systems using gdm 2.28+. After searching the internet we found the
submitted patches from Brian Cameron and Halton Huo for gdm and
consolekit and tried to apply those to the sources used in Ubuntu 9.10.
However, as the work from Brian and Halton is still in progress we found
some still existing problems and thus are reporting them here now.

Am 03.11.09 20:11, schrieb Brian Cameron:

>> Can you please send me a link to the git repository so that I may
>> eventually create own patch files while you are not able to update them
>> at the above locations. Thanks.
>
> The latest code is here:
>
> http://cgit.freedesktop.org/ConsoleKit/log/?h=multi-seat
> http://cgit.freedesktop.org/ConsoleKit/tree/?h=multi-seat
>
> I believe your problems will go away if you use the latest code in that
> branch. Let me know if you have any further problems, or if this fixes
> the issues you have noticed.
>
> The patches at opensolaris.org should be updated to include the latest
> fixes from the above git branch in the next day or two, by the end of
> the week at the latest. Halton or I will make sure that the bugs in
> bugzilla are updated with the latest patches also so that people do not
> use the old patches by accident, if they don't know about git.

Unfortunately the latest patches available in the ConsoleKit git as well
as in the gdm git did not fully solve our problems here.

>>>> -- cut here --
>>>> if (kind == CK_SEAT_KIND_DYNAMIC) {
>>>> g_hash_table_steal (manager->priv->sessions, orig_ssid);
>>>> g_hash_table_remove (manager->priv->sessions, orig_ssid);
>>>> }
>>>> -- cut here --
>>>>
>>>> now it doesn't crash anymore here. After that change we have been
>>>> finally able to log in to our SunRay Server. However, after a short
>>>> test we came across a second problem which I want to outline below:

 >>>

>>> Halton, have we fixed this problem in our latest patches?
>>
>> FYI: It seems this bug is still present, at least in the patch file
>> provided at the above location. I also verified that it still crashes by
>> using your patches. However, after inserting the above
>> g_hash_table_steal() call the segmentation fault vanishes.
>
> Do you still see this problem using the latest code in the git branch?
> I believe that this is one of the issues that Halton recently fixed,
> though I am not sure.

Yes, the problem is still present in the latest code in the git branch.
Here I can perfectly reproduce a crash of console-kit-daemon as soon as
I log into the SRS. However, by adding the above "g_hash_table_steal()"
line right before the remove() finally solves that problem and
console-kit-daemon does not crash anymore.

>>>> 2) With your gdm patches applied it seems that gdm itself does not
>>>> restart the corresponding X server anymore if either the X server
>>>> process is killed via (kill PID) or if the session is killed by
>>>> Ctrl-Bspc-Bspc. This seems to not only be true for the dynamic SunRay
>>>> sessions, but also for any local session (e.g. on display :0). Please
>>>> find attached the debug output where you can hopefully spot the problem
>>>> that gdm tries to start another gdm-simple-slave, however it seems to
>>>> fail and thus it ends up being aborted. Unfortunately we haven't
>>>> found a workaround or fix for this problem yet as we are not that
 >>>> trained with gdm<>consolekit interactions. However, I believe that
 >>>> this could be caused either by the reason that the display isn't
 >>>> freed that quickly so that the new gdm slave can not start a new X
 >>>> server that fast or it might be because there is still something
 >>>> missing in the gdm<>consolekit interaction which causes the
 >>>> X server restart to fail.
 >>>

>>> I believe that this problem is also fixed? Halton, can you confirm?
>>
>> I just grabed the patches from the above directory now and recompiled
>> consolekit 0.3.1 and gdm 2.28.1 for Ubuntu 9.10 here. However, the net
>> result is the same. I am able to connect to the running SunRay service,
>> but as soon as I kill a session with Ctrl+Bspc+Bspc gdm never returns on
>> that display. The same happens with the local display :0, btw. However,
>> the debug output of gdm is now slightly different to the first one I
>> sent to you today. Now gdm is not even trying to restart
>> gdm-simple-slave as it seems. Perhaps you guys have an idea what might
>> cause that.
>
> Do you still see this problem with the latest code in git? Again, I
> think this is an issue that Halton recently fixed, though I am again not
> sure.

Yes, unfortunately this problem is also still present with the latest
changes from the "display-configuration" branch in the gdm git. I can
perfectly verify that by simply manually killing the Xorg process. As
soon as I kill it here a new Xorg will never be automatically started on
display :0 like it is normally done. The same happens on the SRS
displays. Only the initial session gets an X-server process but as soon
as Xnewt/Xorg is killed it never returns on that display.

However, after a longer investigation my colleagues and I tracked the
problem down to the newly added gdm_dynamic_display_finish() function in
daemon/gdm-dynamic-display.c. We found out that there the following
statements are used:

-- cut here --
gdm_dynamic_display_finish (GdmDisplay *display)
{
   g_return_val_if_fail (GDM_IS_DISPLAY (display), FALSE);

   GDM_DISPLAY_CLASS (gdm_dynamic_display_parent_class)->finish (display);

   gdm_display_unmanage (display);

   return TRUE;
}
-- cut here --

However, this seems to cause the display to be finished but never
restarted like it is done with a normal local display or with the
previous unpatched gdm 2.28. Even the local display :0 seems to be
treated as a "dynamic" display now. By replacing the function by the
same one used in daemon/gdm-static-display.c it seems to work:

-- cut here --
gdm_dynamic_display_finish (GdmDisplay *display)
{
   int status;

   g_return_val_if_fail (GDM_IS_DISPLAY (display), FALSE);

   /* Don't call parent's finish since we don't ever
   want to be put in the FINISHED state */

   /* restart dynamic displays */
   gdm_display_unmanage (display);

   status = gdm_display_get_status (display);
   if (status != GDM_DISPLAY_FAILED) {
      gdm_display_manage (display);
   }

   return TRUE;
}
-- cut here --

After that change the local :0 display gets a new Xorg process as soon
as the old one is killed. In addition, with that change the Xserver of
the Sunray Server (Xnewt) also gets respawned correctly.

Finally the above differences allowed us to get SRSS 4.2 running with
gdm 2.28 under Ubuntu 9.10.

It would, however, really be nice if you guys could review my proposed
changes and perhaps integrate them into your latest patchsets and/or
change them in case my changes are not appropriate for the general case.

No matter what, I would like to thank Halton and Brian for getting this
done in gdm 2.28+. And I would like to request that their changes should
be integrated into the latest gdm trunk ASAP so that future Ubuntu
versions (e.g. comming LTS 10.04) ship already with a Sunray compatible
gdm version.

best regards,
jens
--
Jens Langner                                         Ph: [phone]
Forschungszentrum Dresden-Rossendorf e.V.
Institute of Radiopharmacy - PET Center                 J.Langner@...
Germany                                               http://www.fzd.de/
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gdm-list mailing list
gdm-list@...
http://mail.gnome.org/mailman/listinfo/gdm-list

[Halton Huo]

Hi Jens,

With my knowledge so far, you need do following things to let SRSS work
with ConsoleKit and new GDM:

1. Apply the ConsoleKit latest patch
http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/ConsoleKit-01-ck-dynamic.diff

2. Apply the Sunray specific patch
http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/ConsoleKit-02-add-sunray-type.diff

3. Apply the GDM patch
http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/gdm-04-dynamic-display.diff

4. Get gdmdynamic wrapper
http://src.opensolaris.org/source/xref/jds/spec-files/trunk/ext-sources/gdmdynamic

Let me know if you have any issue.

Thanks,
Halton.

On Wed, 2009-11-04 at 15:36 +0100, Jens Langner wrote:

> Hi,
>
> as Brian Cameron asked me to continue the discussion on the gdm mailing
> list I am sending my replay about the latest MultiSeat changes in gdm
> here now.
>
> As an introduction: We are currently trying to get the latest SunRay
> Server (SRS) 4.2 version running with Ubuntu 9.10 which in turn uses gdm
> 2.28. However, as SRS is heavily relying on the previous "gdmdynamic"
> feature the SRS software is not working out-of-the-box anymore with
> systems using gdm 2.28+. After searching the internet we found the
> submitted patches from Brian Cameron and Halton Huo for gdm and
> consolekit and tried to apply those to the sources used in Ubuntu 9.10.
> However, as the work from Brian and Halton is still in progress we found
> some still existing problems and thus are reporting them here now.
>
> Am 03.11.09 20:11, schrieb Brian Cameron:
>
> >> Can you please send me a link to the git repository so that I may
> >> eventually create own patch files while you are not able to update them
> >> at the above locations. Thanks.
> >
> > The latest code is here:
> >
> > http://cgit.freedesktop.org/ConsoleKit/log/?h=multi-seat
> > http://cgit.freedesktop.org/ConsoleKit/tree/?h=multi-seat
> >
> > I believe your problems will go away if you use the latest code in that
> > branch. Let me know if you have any further problems, or if this fixes
> > the issues you have noticed.
> >
> > The patches at opensolaris.org should be updated to include the latest
> > fixes from the above git branch in the next day or two, by the end of
> > the week at the latest. Halton or I will make sure that the bugs in
> > bugzilla are updated with the latest patches also so that people do not
> > use the old patches by accident, if they don't know about git.
>
> Unfortunately the latest patches available in the ConsoleKit git as well
> as in the gdm git did not fully solve our problems here.
>
> >>>> -- cut here --
> >>>> if (kind == CK_SEAT_KIND_DYNAMIC) {
> >>>> g_hash_table_steal (manager->priv->sessions, orig_ssid);
> >>>> g_hash_table_remove (manager->priv->sessions, orig_ssid);
> >>>> }
> >>>> -- cut here --
> >>>>
> >>>> now it doesn't crash anymore here. After that change we have been
> >>>> finally able to log in to our SunRay Server. However, after a short
> >>>> test we came across a second problem which I want to outline below:
>  >>>
> >>> Halton, have we fixed this problem in our latest patches?
> >>
> >> FYI: It seems this bug is still present, at least in the patch file
> >> provided at the above location. I also verified that it still crashes by
> >> using your patches. However, after inserting the above
> >> g_hash_table_steal() call the segmentation fault vanishes.
> >
> > Do you still see this problem using the latest code in the git branch?
> > I believe that this is one of the issues that Halton recently fixed,
> > though I am not sure.
>
> Yes, the problem is still present in the latest code in the git branch.
> Here I can perfectly reproduce a crash of console-kit-daemon as soon as
> I log into the SRS. However, by adding the above "g_hash_table_steal()"
> line right before the remove() finally solves that problem and
> console-kit-daemon does not crash anymore.
>
> >>>> 2) With your gdm patches applied it seems that gdm itself does not
> >>>> restart the corresponding X server anymore if either the X server
> >>>> process is killed via (kill PID) or if the session is killed by
> >>>> Ctrl-Bspc-Bspc. This seems to not only be true for the dynamic SunRay
> >>>> sessions, but also for any local session (e.g. on display :0). Please
> >>>> find attached the debug output where you can hopefully spot the problem
> >>>> that gdm tries to start another gdm-simple-slave, however it seems to
> >>>> fail and thus it ends up being aborted. Unfortunately we haven't
> >>>> found a workaround or fix for this problem yet as we are not that
>  >>>> trained with gdm<>consolekit interactions. However, I believe that
>  >>>> this could be caused either by the reason that the display isn't
>  >>>> freed that quickly so that the new gdm slave can not start a new X
>  >>>> server that fast or it might be because there is still something
>  >>>> missing in the gdm<>consolekit interaction which causes the
>  >>>> X server restart to fail.
>  >>>
> >>> I believe that this problem is also fixed? Halton, can you confirm?
> >>
> >> I just grabed the patches from the above directory now and recompiled
> >> consolekit 0.3.1 and gdm 2.28.1 for Ubuntu 9.10 here. However, the net
> >> result is the same. I am able to connect to the running SunRay service,
> >> but as soon as I kill a session with Ctrl+Bspc+Bspc gdm never returns on
> >> that display. The same happens with the local display :0, btw. However,
> >> the debug output of gdm is now slightly different to the first one I
> >> sent to you today. Now gdm is not even trying to restart
> >> gdm-simple-slave as it seems. Perhaps you guys have an idea what might
> >> cause that.
> >
> > Do you still see this problem with the latest code in git? Again, I
> > think this is an issue that Halton recently fixed, though I am again not
> > sure.
>
> Yes, unfortunately this problem is also still present with the latest
> changes from the "display-configuration" branch in the gdm git. I can
> perfectly verify that by simply manually killing the Xorg process. As
> soon as I kill it here a new Xorg will never be automatically started on
> display :0 like it is normally done. The same happens on the SRS
> displays. Only the initial session gets an X-server process but as soon
> as Xnewt/Xorg is killed it never returns on that display.
>
> However, after a longer investigation my colleagues and I tracked the
> problem down to the newly added gdm_dynamic_display_finish() function in
> daemon/gdm-dynamic-display.c. We found out that there the following
> statements are used:
>
> -- cut here --
> gdm_dynamic_display_finish (GdmDisplay *display)
> {
>    g_return_val_if_fail (GDM_IS_DISPLAY (display), FALSE);
>
>    GDM_DISPLAY_CLASS (gdm_dynamic_display_parent_class)->finish (display);
>
>    gdm_display_unmanage (display);
>
>    return TRUE;
> }
> -- cut here --
>
> However, this seems to cause the display to be finished but never
> restarted like it is done with a normal local display or with the
> previous unpatched gdm 2.28. Even the local display :0 seems to be
> treated as a "dynamic" display now. By replacing the function by the
> same one used in daemon/gdm-static-display.c it seems to work:
>
> -- cut here --
> gdm_dynamic_display_finish (GdmDisplay *display)
> {
>    int status;
>
>    g_return_val_if_fail (GDM_IS_DISPLAY (display), FALSE);
>
>    /* Don't call parent's finish since we don't ever
>    want to be put in the FINISHED state */
>
>    /* restart dynamic displays */
>    gdm_display_unmanage (display);
>
>    status = gdm_display_get_status (display);
>    if (status != GDM_DISPLAY_FAILED) {
>       gdm_display_manage (display);
>    }
>
>    return TRUE;
> }
> -- cut here --
>
> After that change the local :0 display gets a new Xorg process as soon
> as the old one is killed. In addition, with that change the Xserver of
> the Sunray Server (Xnewt) also gets respawned correctly.
>
> Finally the above differences allowed us to get SRSS 4.2 running with
> gdm 2.28 under Ubuntu 9.10.
>
> It would, however, really be nice if you guys could review my proposed
> changes and perhaps integrate them into your latest patchsets and/or
> change them in case my changes are not appropriate for the general case.
>
> No matter what, I would like to thank Halton and Brian for getting this
> done in gdm 2.28+. And I would like to request that their changes should
> be integrated into the latest gdm trunk ASAP so that future Ubuntu
> versions (e.g. comming LTS 10.04) ship already with a Sunray compatible
> gdm version.
>
> best regards,
> jens

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gdm-list mailing list
gdm-list@...
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[Jens Langner]

Hi Halton,

Am 05.11.09 11:26, schrieb Halton Huo:

> With my knowledge so far, you need do following things to let SRSS work
> with ConsoleKit and new GDM:
>
> 1. Apply the ConsoleKit latest patch
> http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/ConsoleKit-01-ck-dynamic.diff
>
> 2. Apply the Sunray specific patch
> http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/ConsoleKit-02-add-sunray-type.diff
>
> 3. Apply the GDM patch
> http://src.opensolaris.org/source/xref/jds/spec-files/trunk/patches/gdm-04-dynamic-display.diff
>
> 4. Get gdmdynamic wrapper
> http://src.opensolaris.org/source/xref/jds/spec-files/trunk/ext-sources/gdmdynamic
>
> Let me know if you have any issue.

Oh sorry. I think I didn't make it clear enough. Of coure I applied the
above mentioned changes. In fact, I already used the latest code from
the repective git repositories. However, the problems I am facing are
still present. So please read through my last email again and take
special attention on my proposed fixes for the two problems that are
still present with your latest changes (crash of console-kit-daemon and
broken behaviour of gdm_dynamic_display_finish function).

best regards,
jens
--
Jens Langner                                         Ph: [phone]
Forschungszentrum Dresden-Rossendorf e.V.
Institute of Radiopharmacy - PET Center                 J.Langner@...
Germany                                               http://www.fzd.de/
_______________________________________________
gdm-list mailing list
gdm-list@...
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