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* [Xenomai] [POWERPC] bug alert with CONFIG_XENO_HW_UNLOCKED_SWITCH, >= kernel 3.4
@ 2013-06-05 10:39 Philippe Gerum
  2013-06-05 11:20 ` Gilles Chanteperdrix
  0 siblings, 1 reply; 3+ messages in thread
From: Philippe Gerum @ 2013-06-05 10:39 UTC (permalink / raw)
  To: Xenomai@xenomai.org


A bad bug has been fixed in the unlocked context switching code for 
powerpc platforms. This affects all I-pipe patches for 3.4 kernels and 
above. The typical manifestation of this bug is random segmentation 
faults in user-space applications (sometimes after hours under stress 
load), usually the Xenomai-dependent ones.

A work around not to change the kernel code is to disable 
CONFIG_XENO_HW_UNLOCKED_SWITCH. Patches for fixing this issue are 
available for 3.5.7 and above:

http://git.xenomai.org/?p=ipipe.git;a=commit;h=614aa59453dacf7693fbb18229c27676c2803dbb
http://git.xenomai.org/?p=ipipe.git;a=commit;h=04ea520ab96a16ec65529a2efed92c9a4a8bda34

You might need this companion patch too: 
http://git.xenomai.org/?p=ipipe.git;a=commit;h=047a21b3b203a1fbfce21284f01e376a2cf54c19

HTH,

-- 
Philippe.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Xenomai] [POWERPC] bug alert with CONFIG_XENO_HW_UNLOCKED_SWITCH, >= kernel 3.4
  2013-06-05 10:39 [Xenomai] [POWERPC] bug alert with CONFIG_XENO_HW_UNLOCKED_SWITCH, >= kernel 3.4 Philippe Gerum
@ 2013-06-05 11:20 ` Gilles Chanteperdrix
  2013-06-05 11:21   ` Gilles Chanteperdrix
  0 siblings, 1 reply; 3+ messages in thread
From: Gilles Chanteperdrix @ 2013-06-05 11:20 UTC (permalink / raw)
  To: Philippe Gerum; +Cc: Xenomai@xenomai.org

On 06/05/2013 12:39 PM, Philippe Gerum wrote:

> 
> A bad bug has been fixed in the unlocked context switching code for 
> powerpc platforms. This affects all I-pipe patches for 3.4 kernels and 
> above. The typical manifestation of this bug is random segmentation 
> faults in user-space applications (sometimes after hours under stress 
> load), usually the Xenomai-dependent ones.
> 
> A work around not to change the kernel code is to disable 
> CONFIG_XENO_HW_UNLOCKED_SWITCH. Patches for fixing this issue are 
> available for 3.5.7 and above:
> 
> http://git.xenomai.org/?p=ipipe.git;a=commit;h=614aa59453dacf7693fbb18229c27676c2803dbb
> http://git.xenomai.org/?p=ipipe.git;a=commit;h=04ea520ab96a16ec65529a2efed92c9a4a8bda34


Well, with these patches, the whole mm switch now runs with irqs off, is
this the intended effect?

-- 
                                                                Gilles.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Xenomai] [POWERPC] bug alert with CONFIG_XENO_HW_UNLOCKED_SWITCH, >= kernel 3.4
  2013-06-05 11:20 ` Gilles Chanteperdrix
@ 2013-06-05 11:21   ` Gilles Chanteperdrix
  0 siblings, 0 replies; 3+ messages in thread
From: Gilles Chanteperdrix @ 2013-06-05 11:21 UTC (permalink / raw)
  To: Philippe Gerum; +Cc: Xenomai@xenomai.org

On 06/05/2013 01:20 PM, Gilles Chanteperdrix wrote:

> On 06/05/2013 12:39 PM, Philippe Gerum wrote:
> 
>>
>> A bad bug has been fixed in the unlocked context switching code for 
>> powerpc platforms. This affects all I-pipe patches for 3.4 kernels and 
>> above. The typical manifestation of this bug is random segmentation 
>> faults in user-space applications (sometimes after hours under stress 
>> load), usually the Xenomai-dependent ones.
>>
>> A work around not to change the kernel code is to disable 
>> CONFIG_XENO_HW_UNLOCKED_SWITCH. Patches for fixing this issue are 
>> available for 3.5.7 and above:
>>
>> http://git.xenomai.org/?p=ipipe.git;a=commit;h=614aa59453dacf7693fbb18229c27676c2803dbb
>> http://git.xenomai.org/?p=ipipe.git;a=commit;h=04ea520ab96a16ec65529a2efed92c9a4a8bda34
> 
> 
> Well, with these patches, the whole mm switch now runs with irqs off, is
> this the intended effect?
> 

Sorry, misread the code.

-- 
                                                                Gilles.


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2013-06-05 11:21 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2013-06-05 10:39 [Xenomai] [POWERPC] bug alert with CONFIG_XENO_HW_UNLOCKED_SWITCH, >= kernel 3.4 Philippe Gerum
2013-06-05 11:20 ` Gilles Chanteperdrix
2013-06-05 11:21   ` Gilles Chanteperdrix

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