On Thu, 8 Sep 2016, Fenghua Yu wrote:
> +/*
> + * cbm_update_msrs() - Updates all the existing IA32_L3_MASK_n MSRs
> + * which are one per CLOSid on the current package.
> + */
> +static void cbm_update_msrs(void *dummy)
> +{
> + int maxid = boot_cpu_data.x86_cache_max_closid;
> + struct rdt_remote_data info;
> + unsigned int i;
> +
> + for (i = 0; i < maxid; i++) {
> + if (cctable[i].clos_refcnt) {
> + info.msr = CBM_FROM_INDEX(i);
> + info.val = cctable[i].cbm;
> + msr_cpu_update(&info);
> + }
> + }
> +}
> +
> +static int intel_rdt_online_cpu(unsigned int cpu)
> +{
> + struct intel_pqr_state *state = &per_cpu(pqr_state, cpu);
> +
> + state->closid = 0;
> + mutex_lock(&rdtgroup_mutex);
> + /* The cpu is set in root rdtgroup after online. */
> + cpumask_set_cpu(cpu, &root_rdtgrp->cpu_mask);
> + per_cpu(cpu_rdtgroup, cpu) = root_rdtgrp;
> + /*
> + * If the cpu is first time found and set in its siblings that
-ENOPARSE
> + * share the same cache, update the CBM MSRs for the cache.
> + */
> + if (rdt_cpumask_update(cpu))
> + smp_call_function_single(cpu, cbm_update_msrs, NULL, 1);
This smp_call_function() is a pointless exercise. online callbacks are
guaranteed to run on @cpu.
> + mutex_unlock(&rdtgroup_mutex);
> +}
> +
> +static int clear_rdtgroup_cpumask(unsigned int cpu)
> +{
> + struct list_head *l;
> + struct rdtgroup *r;
> +
> + list_for_each(l, &rdtgroup_lists) {
> + r = list_entry(l, struct rdtgroup, rdtgroup_list);
> + if (cpumask_test_cpu(cpu, &r->cpu_mask)) {
> + cpumask_clear_cpu(cpu, &r->cpu_mask);
> + return 0;
> + }
> + }
> +
> + return -EINVAL;
What's the point of the return value if it gets ignored anyway.
> +}
> +
> +static int intel_rdt_offline_cpu(unsigned int cpu)
> +{
> + int i;
> +
> + mutex_lock(&rdtgroup_mutex);
> + if (!cpumask_test_and_clear_cpu(cpu, &rdt_cpumask)) {
> + mutex_unlock(&rdtgroup_mutex);
> + return;
> + }
> +
> + cpumask_and(&tmp_cpumask, topology_core_cpumask(cpu), cpu_online_mask);
> + cpumask_clear_cpu(cpu, &tmp_cpumask);
> + i = cpumask_any(&tmp_cpumask);
> +
> + if (i < nr_cpu_ids)
> + cpumask_set_cpu(i, &rdt_cpumask);
> +
> + clear_rdtgroup_cpumask(cpu);
> + mutex_unlock(&rdtgroup_mutex);
> +}
> +
> static int __init intel_rdt_late_init(void)
> {
> struct cpuinfo_x86 *c = &boot_cpu_data;
> @@ -169,6 +247,13 @@ static int __init intel_rdt_late_init(void)
>
> for_each_online_cpu(i)
> rdt_cpumask_update(i);
> +
> + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
> + "AP_INTEL_RDT_ONLINE",
> + intel_rdt_online_cpu, intel_rdt_offline_cpu);
Why are you using nocalls() here? cpuhp_setup_state() will invoke
intel_rdt_online_cpu() on every online cpu.
And you just call rdt_cpumask_update() for each cpu. What is doing the rest
of the cpu initialization (cpu_rdtgroup, root_rtgroup->cpu_mask) ????
> + if (err < 0)
> + goto out_err;
Oh well.....
Thanks,
tglx
