[PATCH 1/5] Fix spurious segmentation faults

[Sebastien Jan]

On 07/02/2010 07:06 AM, Bryan Wu wrote:
> On 07/01/2010 10:15 PM, Sebastien Jan wrote:
>> On 07/01/2010 07:07 AM, Bryan Wu wrote:
>>> Sebjan,
>>>
>>> I heard this bug from Ogra before. And this patch touches the ARM common MM
>>> code, I also failed to find it in upstream mainline.
>>>
>>> I think if you or Rob can pointed out in the git log, it is better for us to review.
>>>
>>> Ogra, do we have a bug in LP about this?
>>>
>>> BTW, CONFIG_CPU_USE_DOMAINS=n in our ti-omap4 config
>>>
>>> Thanks,
>>> -Bryan
>>>
> 
> [snip]
> 
>>
>> Right, I shall have provided this info in the commit itself:
>> An early version of the following patch from Catalin was integrated into our omap4 branch:
>> http://www.spinics.net/lists/arm-kernel/msg91260.html
>> (see commit f22c4b02)
>>
> 
> Which tree is this patch in? I didn't find it.

This commit (f22c4b02) appears in the kernel-ubuntu tree (in the for-ubuntu-2.6.34 branch for example) (and comes from our kernel-omap4 tree, both on dev.omapzoom.org).
See this link: http://dev.omapzoom.org/?p=integration/kernel-ubuntu.git;a=commit;h=f22c4b0221b283f05a648d35f19facf80d8a0b23

>> But there have been some updates to this patch series, which the current patch aims to cover, as it fixes some very ugly side effects.
>>
> 
> Yeah, I think this patch will be helpful, but we need some testing. Do we have
> launchpad bug tracker of this bug? Ogra and Lee, are you guys aware of this bug?
> I am not playing with the Maverick rootfs.
> 
>> Regarding patch author: I specified Rob as he did the investigations on the segfault we had, and find out the missing parts. We may have to credit Catalin instead/additionaly.
> 
> Rob, thanks for fixing this. But we need know more information about the
> original patches and the status of this patch? Will this patch in mainline or in
> the OMAP4 upstream queue? That will be much easier for us to review.

The 1st version of this patch series has been integrated into our omap4 tree (see above commit information).
Since then, new versions of this series are being discussed on the ARM ML [1]. From what I can read, it seems to be a proposal for the 2.6.36 merge window.

Rob's patch contains a part of the new patch series, which fixes a memory related issue (which used to cause the segfaults when using git v1.7.0 for example).
Without this patch, I also used to see segfaults when using dpkg or gcc, making my maverick FS impossible to use for intensive build tasks.
With this patch, I was able to build the latest kernel image on my omap4 board.

We plan to integrate the complete updated patch series in a coming update.


[1] http://www.spinics.net/lists/arm-kernel/msg91260.html
    full thread: http://www.spinics.net/lists/arm-kernel/msg91259.html