On Thu, 20 Mar 2008 16:02:11 -0700
Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
In a Xen system, when a new pagetable is about to be put in use it is "pinned", meaning that each page in the pagetable is registered with
the hypervisor. This is done in arch/x86/xen/mmu.c:pin_page().
In order to make this efficient, the hypercalls for pinning are
batched, so that multiple pages are submitted at once in a single
multicall. While a page is batched pending the hypercall, its
corresponding pte_lock is held.
This means that the code can end up holding multiple pte locks at
once, though it is guaranteed to never try to hold the same lock at
once. However, because these locks are in the same lock class, I get
a spurious warning from lockdep. Is there some way I can get rid of
this warning?
what's the ordering guarantee between these locks ?