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Date: Thu, 15 Jan 2009 15:12:15 +0100
From: Jan Kiszka <jan.kiszka@domain.hid>
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Subject: Re: [Xenomai-core] Pending patches
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To: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Cc: xenomai-core <xenomai@xenomai.org>

Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Gilles Chanteperdrix wrote:
>>>> Jan Kiszka wrote:
>>>>> Hi,
>>>>>
>>>>> currently I have the following six patches in my assorted queue
>>>>> (git://git.kiszka.org/xenomai.git queue/assorted). All have been posted
>>>>> before, I just rebased them since then a few times. Should I repost
>>>>> any/all of them (would be no problem), or are some already queued for
>>>>> potential merge?
>>>>>
>>>>> Jan
>>>>>
>>>>> (...)
>>>>> commit a631ab2c531d5e381ba8a0a59bf301a0276d9f99
>>>>> Author: Jan Kiszka <jan.kiszka@domain.hid>
>>>>> Date:   Thu Jan 15 11:10:24 2009 +0100
>>>>>
>>>>>     POSIX: Do not auto-shadow main with dlopen enabled
>>>>>     
>>>>>     Don't perform auto-shadowing in POSIX skin if we might be loaded via
>>>>>     dlopen. Otherwise the wrong thread, the undefined dlopen caller, may be
>>>>>     (re-)shadowed, assigning wrong scheduling settings.
>>>>>     
>>>>>     Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>>>>
>>>>>  src/skins/posix/init.c |   43 ++++++++++++++++++++++++++++---------------
>>>>>  1 files changed, 28 insertions(+), 15 deletions(-)
>>>>>
>>>>> commit 91ae3da822ca558804bf33be4d164ea4c2667c1b
>>>>> Author: Jan Kiszka <jan.kiszka@domain.hid>
>>>>> Date:   Thu Jan 15 11:10:24 2009 +0100
>>>>>
>>>>>     Replace --without-__tread with --enable-dlopen-skins
>>>>>     
>>>>>     In practice, you only want to disable __thread support when Xenomai skin
>>>>>     libraries should be loadable via dlopen. Therefore rename the related
>>>>>     configure switch accordingly.
>>>>>     
>>>>>     Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
>>>>>
>>>> Nack these two ones: one of the gcc bugs I have found on ARM is related
>>>> to __thread (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38815). So,
>>>> even though I have found a work around for the bug, I am not sure that
>>>> it works all the time, so disabling __thread on ARM is safer. Especially
>>>> since __thread does not bring any performance improvement over
>>>> pthread_(get|set)specific on ARM.
>>> Actually, I am not opposed to the first, only to the second.
>> OK, will you or should I apply the do-not-auto-shadow patch?
>>
>> Regarding the second one: If the option should continue to be named
>> --without-__thread (because of ARM), then we need at the bare minimum a
>> documentation of the correlation with dlopen. BTW, any concerns to apply
>> the "Mark libs nodlopen" fix?
> 
> Maybe we could add the dlopen option which would disable shadowing of
> the main thread and unselect __thread ?

Sounds good, will do this.

Jan

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