Re: [PATCH] mm/hugetlb: allow crashkernel to reuse hugetlb CMA memory

[David Hildenbrand (Arm)]

On 11/4/26 16:20, Kiryl Shutsemau wrote:
> On Wed, Nov 04, 2026 at 06:27:27AM -0800, Usama Arif wrote:
>> Use a separate suffix to make the exclusion of existing HugeTLB
>> allocations from the vmcore an explicit choice.
> 
> The crashkernel=size,cma documentation already says that pages allocated
> from the range are not in the vmcore and that it should not be used if
> dumping of userspace memory is intended. HugeTLB pages are userspace
> memory. I don't see what a new suffix makes explicit that ",cma" does
> not already.
> 
> Why not let crashkernel=size,cma take hugetlb CMA first and reserve a
> dedicated area only for what hugetlb CMA does not cover? With
> hugetlb_cma=6G crashkernel=2G,cma there would be no extra CMA at all.

Hiding that complexity from the user would indeed be nice.

-- 
Cheers,

David