> >pool_put is not only one which has the assumption.
> >eg. uvm_km_kmemalloc1, in the case of UVM_KMF_NOWAIT.
> >and i guess there're more...
> 
> But uvm_km_kmemalloc1 shouldn't be splitting map entries.  It might need to
> extend or allocate a new map entry.  But if it can't, then it should fail the
> allocation.  So I don't see an issue here.

it calls uvm_unmap when uvm_pagealloc failed.

YAMAMOTO Takashi