Re: [GIT PULL] KVM changes for 3.12

[Stephen Warren <swarren@wwwdotorg.org>]

On 09/04/2013 04:38 AM, Gleb Natapov wrote:
> Copying Marek, Aneesh and Alex since this came through PPC kvm tree.
> 
> On Wed, Sep 04, 2013 at 12:18:28PM +0200, Thierry Reding wrote:
>> On Tue, Sep 03, 2013 at 03:10:46PM +0300, Gleb Natapov wrote:
>> [...]
>>> Aneesh Kumar K.V (5):
>>>       mm/cma: Move dma contiguous changes into a seperate config
>>
>> Hi Gleb,
>>
>> This commit is going to cause runtime regressions on various ARM
>> platforms because it renames a symbol but fails to update all default
>> configurations that select the symbol. A quick grep shows that three ARM
>> platforms are affected:
>>
>> 	$ git grep CONFIG_CMA=y
>> 	arch/arm/configs/keystone_defconfig:CONFIG_CMA=y
>> 	arch/arm/configs/omap2plus_defconfig:CONFIG_CMA=y
>> 	arch/arm/configs/tegra_defconfig:CONFIG_CMA=y
>>
>> I've been digging around a bit and it seems like the original patch from
>> Aneesh had the defconfig changes but they were dropped because they "...
>> require separate handling to avoid pointless merge conflicts."[0]
>>
> Marek, that's your words. What do you think about ARM problem?
> 
>> While I can't speak for Keystone or OMAP, at least on Tegra this causes
>> issues because we use CMA for framebuffer allocation. Since we only have
>> CMA selected but not the new DMA_CMA, large DMA allocations will fail.
>>
> Make config suppose to ask you about new option though, does it?

"make oldconfig" quite possibly might, but "make tegra_defconfig"
doesn't, and "make tegra_defconfig; make zImage" is a workflow that has
historically generated a perfectly working kernel for Tegra, and hence
people use that flow.