vmalloc or kmalloc for 16k memory space
 

I'm writing a device driver. When the device is going to be suspended, the driver allocates a 16k memory space. When the device is going to be resumed, the driver frees this memory space. The suspend/resume may happen quite often. My problem is whether to use vmalloc or kmalloc for this allocation. kmalloc is faster, but I'm worried about that frequently allocating & releasing a 16k memory space easily leads to a failure in allocation. vmalloc doesn't have this problem, but it's not as efficient as kmalloc.

For 16k memory, do you use it for hardware operation? If not, vmalloc should be Ok.

No hardware operation, but vmalloc is expensive, it has to setup page tables.

You can use mempool to avoid frequently allocating & releasing physically. The pool always hold the memory even if the memory is freed.