Re: [PATCH v7u1 26/31] x86: Don't enable swiotlb if there is notenough ram for it

From: Yinghai Lu
Date: Mon Jan 07 2013 - 16:30:11 EST

On Mon, Jan 7, 2013 at 12:32 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>> 2). The check for 1MB is suspect. Why only 1MB? You mentioned it is
>> b/c of crashkernel_low=72M (which I am not seeing in v3.8 kernel-parameters.txt?
>> Is that part of your mega-patchset?). Anyhow, there seems to be a disconnect -
>> what if the user supplied crashkernel_low=27M? Perhaps the 'is_enough'
>> should also parse the bootparams to double-check that there is enough
>> low-mem space? But then if the kernel grows then 72M might not be enough -
>> you might need 82M with 3.9.
> again, could with memmap= include or exclude case, so parse boot command line
> is not going to handle all the case.

replace the hardcoded 1M checking, please check attached -v3.



Attachment: auto_switch_off_swiotlb_v3.patch
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