Considering that several systems have trouble allocating large
chunks of continous memory, for the slab allocator? I think using
vmalloc as a fallback for kmalloc either indirectly in kmalloc or
indirectly in the code itself is a good idea that shouldn't be too
difficult.
The answer is a flat out no. Think TLB coherency on SMP boxes, Linux
wins so much performance because it avoids this entire problem by
having nearly no kernel address space mapping changes done ever while
the system is running.
vmalloc() should be used rarely, if at all, and certainly not for any
critical operation (performance wise)
Linus will probably preach something along these lines as well...
Later,
David S. Miller
davem@dm.cobaltmicro.com