From: Boris Ostrovsky Date: Thu, 11 Apr 2013 17:59:52 +0000 (-0400) Subject: x86/mm: Flush lazy MMU when DEBUG_PAGEALLOC is set X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=26564600c9e88c6572a5e6ef5ae9121907edfb7f;p=deliverable%2Flinux.git 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 --- 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