----- h...@zytor.com wrote: > On 02/26/2013 02:56 PM, Boris Ostrovsky wrote: > > 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.ostrov...@oracle.com> > > --- > > 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 ca1f1c2..7b3216e 100644 > > --- a/arch/x86/mm/pageattr.c > > +++ b/arch/x86/mm/pageattr.c > > @@ -1369,6 +1369,8 @@ 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 > > > > This sounds like a critical fix, i.e. a -stable candidate. Am I > correct?
I considered copying stable but then I decided that this is a debugging feature --- kernel_map_pages() is only defined if CONFIG_DEBUG_PAGEALLOC is set and my thinking was that stable kernels usually don't do this. -boris -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
