On 2022/11/17 6:39, Frederic Weisbecker wrote:
> On Fri, Nov 11, 2022 at 09:07:07PM +0800, Zhen Lei wrote:
>> @@ -262,6 +279,8 @@ struct rcu_data {
>> short rcu_onl_gp_flags; /* ->gp_flags at last online. */
>> unsigned long last_fqs_resched; /* Time of last rcu_resched(). */
>> unsigned long last_sched_clock; /* Jiffies of last rcu_sched_clock_irq(). */
>> + struct rcu_snap_record snap_record; /* Snapshot of core stats at half of */
>> + /* the first RCU stall timeout */
>
> This should be under #ifdef CONFIG_RCU_CPU_STALL_CPUTIME
This will not work for now because we also support boot option rcupdate.rcu_cpu_stall_cputime.
>
>> +static void print_cpu_stat_info(int cpu)
>> +{
>> + struct rcu_snap_record rsr, *rsrp;
>> + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
>> + struct kernel_cpustat *kcsp = &kcpustat_cpu(cpu);
>> +
>> + if (!rcu_cpu_stall_cputime)
>> + return;
>> +
>> + rsrp = &rdp->snap_record;
>> + if (rsrp->gp_seq != rdp->gp_seq)
>> + return;
>> +
>> + rsr.cputime_irq = kcpustat_field(kcsp, CPUTIME_IRQ, cpu);
>> + rsr.cputime_softirq = kcpustat_field(kcsp, CPUTIME_SOFTIRQ, cpu);
>> + rsr.cputime_system = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu);
>> +
>> + pr_err("\t hardirqs softirqs csw/system\n");
>> + pr_err("\t number: %8ld %10d %12lld\n",
>> + kstat_cpu_irqs_sum(cpu) - rsrp->nr_hardirqs,
>> + kstat_cpu_softirqs_sum(cpu) - rsrp->nr_softirqs,
>> + nr_context_switches_cpu(cpu) - rsrp->nr_csw);
>> + pr_err("\tcputime: %8lld %10lld %12lld ==> %lld(ms)\n",
>> + div_u64(rsr.cputime_irq - rsrp->cputime_irq, NSEC_PER_MSEC),
>> + div_u64(rsr.cputime_softirq - rsrp->cputime_softirq, NSEC_PER_MSEC),
>> + div_u64(rsr.cputime_system - rsrp->cputime_system, NSEC_PER_MSEC),
>> + jiffies64_to_msecs(jiffies - rsrp->jiffies));
>
> jiffies_to_msecs() should be enough.
OK, thanks.
>
> Thanks.
>
> .
>
--
Regards,
Zhen Lei
