Re: An cma optimization patch is used for cma_[alloc|free].

From: David Hildenbrand
Date: Fri Aug 13 2021 - 03:45:13 EST


On 13.08.21 09:00, Jichao Zou wrote:
Pre-allocate CMA memory that configured in device
tree, this greatly improves the CMA memory
allocation efficiency, cma_[alloc|free] is less
than 1ms, old way is took a few ms to tens or
hundreds ms.


Please send patches as proper emails (man git-format-patch; man git-send-email).

What you propose is turning cma reservations into something comparable to permanent boottime allocations. From the POV of the buddy, the pages are always allocated and cannot be repurposed for e.g., movable allocations until *actually* allocated via CMA.

I don't think we want this behavior upstream.

--
Thanks,

David / dhildenb