On Mon, May 8, 2017 at 8:34 AM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > On 05/07/2017 05:38 AM, Andy Lutomirski wrote: >> diff --git a/mm/rmap.c b/mm/rmap.c >> index f6838015810f..2e568c82f477 100644 >> --- a/mm/rmap.c >> +++ b/mm/rmap.c >> @@ -579,25 +579,12 @@ void page_unlock_anon_vma_read(struct anon_vma *anon_vma) >> void try_to_unmap_flush(void) >> { >> struct tlbflush_unmap_batch *tlb_ubc = ¤t->tlb_ubc; >> - int cpu; >> >> if (!tlb_ubc->flush_required) >> return; >> >> - cpu = get_cpu(); >> - >> - if (cpumask_test_cpu(cpu, &tlb_ubc->cpumask)) { >> - count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); >> - local_flush_tlb(); >> - trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL); >> - } >> - >> - if (cpumask_any_but(&tlb_ubc->cpumask, cpu) < nr_cpu_ids) >> - flush_tlb_others(&tlb_ubc->cpumask, NULL, 0, TLB_FLUSH_ALL); >> - cpumask_clear(&tlb_ubc->cpumask); >> tlb_ubc->flush_required = false; >> tlb_ubc->writable = false; >> - put_cpu(); >> } >> >> /* Flush iff there are potentially writable TLB entries that can race with IO */ >> @@ -613,7 +600,7 @@ static void set_tlb_ubc_flush_pending(struct mm_struct *mm, bool writable) >> { >> struct tlbflush_unmap_batch *tlb_ubc = ¤t->tlb_ubc; >> >> - cpumask_or(&tlb_ubc->cpumask, &tlb_ubc->cpumask, mm_cpumask(mm)); >> + arch_tlbbatch_add_mm(&tlb_ubc->arch, mm); >> tlb_ubc->flush_required = true; >> >> /* > > Looking at this patch in isolation, how can this be safe? It removes > TLB flushes from the generic code. Do other patches in the series fix > this up? Hmm? Unless I totally screwed this up, this patch just moves the flushes around -- it shouldn't remove any flushes. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>