diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 26542cc17043..e4156e37aa71 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -712,15 +712,50 @@ void tlb_flush_remove_tables_local(void *arg) } } +static void mm_fill_lazy_tlb_cpu_mask(struct mm_struct *mm, + struct cpumask *lazy_cpus) +{ + int cpu; + + for_each_cpu(cpu, mm_cpumask(mm)) { + if (!per_cpu(cpu_tlbstate.is_lazy, cpu)) + cpumask_set_cpu(cpu, lazy_cpus); + } +} + void tlb_flush_remove_tables(struct mm_struct *mm) { int cpu = get_cpu(); - /* - * XXX: this really only needs to be called for CPUs in lazy TLB mode. - */ - if (cpumask_any_but(mm_cpumask(mm), cpu) < nr_cpu_ids) - smp_call_function_many(mm_cpumask(mm), tlb_flush_remove_tables_local, (void *)mm, 1); + cpumask_var_t lazy_cpus; + if (cpumask_any_but(mm_cpumask(mm), cpu) >= nr_cpu_ids) { + put_cpu(); + return; + } + + if (!zalloc_cpumask_var(&lazy_cpus, GFP_ATOMIC)) { + /* + * If the cpumask allocation fails, do a brute force flush + * on all the CPUs that have this mm loaded. + */ + smp_call_function_many(mm_cpumask(mm), + tlb_flush_remove_tables_local, (void *)mm, 1); + put_cpu(); + return; + } + + /* + * CPUs with !is_lazy either received a TLB flush IPI while the user + * pages in this address range were unmapped, or have context switched + * and reloaded %CR3 since then. + * + * Shootdown IPIs at page table freeing time only need to be sent to + * CPUs that may have out of date TLB contents. + */ + mm_fill_lazy_tlb_cpu_mask(mm, lazy_cpus); + smp_call_function_many(lazy_cpus, + tlb_flush_remove_tables_local, (void *)mm, 1); + free_cpumask_var(lazy_cpus); put_cpu(); }