Re: [PATCH v3 5/5] mm/slub: do not create dma-kmalloc if no managed pages in DMA zone

john.p.donnelly
2021-12-14T17:08:09Z

On 12/14/21 10:31 AM, Christoph Hellwig wrote:
> On Mon, Dec 13, 2021 at 08:27:12PM +0800, Baoquan He wrote:
>> Dma-kmalloc will be created as long as CONFIG_ZONE_DMA is enabled.
>> However, it will fail if DMA zone has no managed pages. The failure
>> can be seen in kdump kernel of x86_64 as below:
>
> Please just switch the sr allocation to use GFP_KERNEL without GFP_DMA.
> The block layer will do the proper bounce buffering underneath for the
> very unlikely case that we're actually using the single HBA driver that
> has ISA DMA addressing limitations.
>
> Same for the ch drive, btw.

Hi,

Is CONFIG_ZONE_DMA even needed anymore in x86_64 ?