Re: [PATCH v4 1/3] mm_zone: add function to check if managed dma zone exists

On 12/23/21 3:44 AM, Baoquan He wrote: In some places of the current kernel, it assumes that dma zone must have managed pages if CONFIG_ZONE_DMA is enabled. While this is not always true. E.g in kdump kernel of x86_64, only low 1M is presented and locked down at very early stage of boot, so that

[PATCH v4 1/3] mm_zone: add function to check if managed dma zone exists

In some places of the current kernel, it assumes that dma zone must have managed pages if CONFIG_ZONE_DMA is enabled. While this is not always true. E.g in kdump kernel of x86_64, only low 1M is presented and locked down at very early stage of boot, so that there's no managed pages at all in DMA zo