Re: [PATCH 05/12] time: Add debugging checks to warn if we see delays

[Peter Zijlstra]

On Thu, Jan 22, 2015 at 04:09:20PM -0800, John Stultz wrote:
> +#ifdef CONFIG_DEBUG_TIMEKEEPING
> +static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
> +{
> +
> +	cycle_t max_cycles = tk->tkr.clock->max_cycles;
> +	const char *name = tk->tkr.clock->name;
> +
> +	if (offset > max_cycles)
> +		printk_deferred("ERROR: cycle offset (%lld) is larger then"
> +			" allowed %s max_cycles (%lld)\n",
> +			offset, name, max_cycles);
> +	else if (offset > (max_cycles >> 1))
> +		printk_deferred("WARNING: cycle offset (%lld) is past"
> +			" the %s 50%% safety margin (%lld)\n",
> +			offset, name, max_cycles>>1);
> +}
> +#else
> +#define timekeeping_check_update(x, y)

static inline void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) { }

Would preserve argument type checks. The only argument for using a macro
here would be to avoid evaluating the arguments, but that's not an issue
in this case afaict.

> +#endif
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/