Re: [PATCH v3 06/11] x86/mm: Rework lazy TLB mode and TLB freshness tracking

[Boris Ostrovsky]

diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 1d7a7213a310..f5df56fb8b5c 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -1005,8 +1005,7 @@ static void xen_drop_mm_ref(struct mm_struct *mm)
        /* Get the "official" set of cpus referring to our pagetable. */
        if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
                for_each_online_cpu(cpu) {
-                       if (!cpumask_test_cpu(cpu, mm_cpumask(mm))
-                           && per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
+                       if (per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
                                continue;
                        smp_call_function_single(cpu, drop_mm_ref_this_cpu, mm, 
1);
                }

I wonder then whether
        cpumask_copy(mask, mm_cpumask(mm));
immediately below is needed.

-boris