On Thu, 15 Feb 2007 23:08:02 -0800 Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
Andrew Morton wrote:
This won't work when CONFIG_PREEMPT=y. The pagefault handler will see
in_atomic() and will scram.
Is there some other way to get the pagetable populated for the address
If you really need to run atomically, that gets ugly. Even of one were to
run handle_mm_fault() by hand, it still needs to allocate memory.
Two ugly options might be:
a) touch all the pages, then go atomic, then touch them all again. If
one of them faults (ie: you raced with swapout) then go back and try
again. Obviously susceptible to livelocking.
b) Do get_user_pages() against all the pages, then go atomic, then do
put_page() against them all. Of course, they can immediately get
But that function's already racy against swapout and I guess it works OK. I don't have clue what it is actually trying to do, so I'm guessing madly