On Fri, Aug 24, 2018 at 03:13:32PM +0200, Peter Zijlstra wrote: > + * HAVE_RCU_TABLE_FREE > + * > + * This provides tlb_remove_table(), to be used instead of tlb_remove_page() > + * for page directores (__p*_free_tlb()). This provides separate freeing of > + * the page-table pages themselves in a semi-RCU fashion (see comment below). > + * Useful if your architecture doesn't use IPIs for remote TLB invalidates > + * and therefore doesn't naturally serialize with software page-table walkers. > + * > + * HAVE_RCU_TABLE_INVALIDATE > + * > + * This makes HAVE_RCU_TABLE_FREE call tlb_flush_mmu_tlbonly() before freeing > + * the page-table pages. Required if you use HAVE_RCU_TABLE_FREE and your > + * architecture uses the Linux page-tables natively. Writing that also made me think we maybe should've negated that option.