Q:

can vmalloc pages be swapping pages?

basically vmalloc pages cannot be swap out, so it's not in the LRU list. is it possible to add a vmalloc page to the LRU list? so that kernel can stats the usage on that page and swap out it if it's not frequently used?
Thanks

A:

vmalloc() gives service to the kernel core, and some paths in the kernel which access the vmalloc()-ed memory can not sleep nor can't take any lock nor can't be preempted. If a accessing vmalloc()-ed page is swaped out, these paths will have to compete some locks and try to swap it in, they may also need to be preempted or sleep, so these paths enter a bug situation which can't be fix.
So the answer is "NO".

