From 26564600c9e88c6572a5e6ef5ae9121907edfb7f Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Thu, 11 Apr 2013 13:59:52 -0400 Subject: [PATCH] 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 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 --- arch/x86/mm/pageattr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 7896f7190fda..fb4e73ec24d8 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -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 -- 2.20.1