Commit 26564600 authored Apr 11, 2013 by Boris Ostrovsky Committed by Ingo Molnar Apr 12, 2013

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>

parent 18699739

arch/x86/mm/pageattr.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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

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