On Tue, 20 Jun 2017, Daniel Lezcano wrote:
> struct irq_timings {
> u64 values[IRQ_TIMINGS_SIZE]; /* our circular buffer */
> - unsigned int count; /* Number of interruptions since last inspection */
> + int count; /* Number of interruptions since last inspection */
WTF?
> + ret = irq_timings_alloc(irq);
> + if (ret) {
> + pr_warn("Failed to allocate irq timing stats for irq%d (%d)",
> + irq, ret);
That error code is -ENOMEM always, right?
> @@ -19,6 +25,18 @@ DEFINE_STATIC_KEY_FALSE(irq_timing_enabled);
>
> DEFINE_PER_CPU(struct irq_timings, irq_timings);
>
> +struct irqt_stat {
> + u64 ne; /* next event */
Kernel doc format for struct documentation please. And with proper struct
member names you can spare that whole documentation.
What the heck is wrong with next_evt, last_ts, nr_samples or such ?
> + u64 lts; /* last timestamp */
> + u64 variance; /* variance */
> + u32 avg; /* mean value */
> + u32 count; /* number of samples */
> + int anomalies; /* number of consecutives anomalies */
> + int valid; /* behaviour of the interrupt */
> +};
That would be too intuitive and spare a permanent lookup of the fricking
acronyms, right?
> +/**
> + * irqs_update - update the irq timing statistics with a new timestamp
> + *
> + * @irqs: an irqt_stat struct pointer
> + * @ts: the new timestamp
> + *
> + * ** This function must be called with the local irq disabled **
No need to yell here. And if you really fear that it's called with
interrupts enabled, then add a proper debug check.
Also instead of making mandatory statements it's better to explain WHY.
> +/**
> + * irq_timings_next_event - Return when the next event is supposed to arrive
> + *
> + * *** This function must be called with the local irq disabled ***
Idem.
> +void irq_timings_free(int irq)
> +{
> + struct irqt_stat __percpu *s;
> +
> + s = idr_find(&irqt_stats, irq);
> + if (s) {
> + free_percpu(s);
> + idr_remove(&irqt_stats, irq);
> + }
> +}
> +
> +int irq_timings_alloc(int irq)
> +{
> + int id;
> + struct irqt_stat __percpu *s;
struct irqt_stat __percpu *s;
int id;
Please ...
Don't bother to offer me a git tree, I'm going to apply that manually
anyway.
Thanks,
tglx
