Re: [PATCH] vmalloc: add __alloc_vm_area() for optimizing vmap stack

[Christoph Hellwig]

This looks fine in general, but a few comments:

 - can you split adding the new function from switching over the fork
   code?
 - at least kasan and vmalloc_user/vmalloc_32_user use very similar
   patterns, can you switch them over as well?
 - the new __alloc_vm_area looks very different from alloc_vm_area,
   maybe it needs a better name?  vmalloc_range_area for example?
 - when you split an existing function please keep the more low-level
   function on top of the higher level one that calls it.