在Linux内核中选择内存分配API以频繁分配大内存

Question

I have to allocate huge amount of memory frequently in my kernel driver. Which memory allocation api is better to use and why ?

Answer 1

If you need large allocations, kmalloc() is not a good idea, because once the physical address space has become fragmented, large kmalloc() allocations will frequently fail.

So vmalloc() / vfree() is most probably the way to go - unless you need to share the buffer with the hardware device, in which case look into the CMA (Contiguous Memory Allocator), dma_alloc_from_contiguous() / dma_release_from_contiguous() .