x86/mm: Flush lazy MMU when DEBUG_PAGEALLOC is set

When CONFIG_DEBUG_PAGEALLOC is set page table updates made by
kernel_map_pages() are not made visible (via TLB flush)
immediately if lazy MMU is on. In environments that support lazy
MMU (e.g. Xen) this may lead to fatal page faults, for example,
when zap_pte_range() needs to allocate pages in
__tlb_remove_page() -> tlb_next_batch().

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: konrad.wilk@oracle.com
Link: http://lkml.kernel.org/r/1365703192-2089-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Boris Ostrovsky 2013-04-11 13:59:52 -04:00 committed by Ingo Molnar
parent 18699739b6
commit 26564600c9

View file

@ -1413,6 +1413,8 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
* but that can deadlock->flush only current cpu:
*/
__flush_tlb_all();
arch_flush_lazy_mmu_mode();
}
#ifdef CONFIG_HIBERNATION