Re: [patch v12 07/13] task isolation: sync vmstats conditional on changes

Thomas Gleixner
2022-04-27T08:04:05Z

On Tue, Mar 15 2022 at 12:31, Marcelo Tosatti wrote:
>
> +#ifdef CONFIG_TASK_ISOLATION
> +struct static_key vmstat_sync_enabled;

jump_label.h:

"The use of 'struct static_key' directly, is now DEPRECATED."

> +DEFINE_PER_CPU_ALIGNED(bool, vmstat_dirty);
> +
> +static inline void mark_vmstat_dirty(void)
> +{
> + if (!static_key_false(&vmstat_sync_enabled))
> + return;
> +
> + raw_cpu_write(vmstat_dirty, true);

What's the justification for raw_cpu_write()?

>
> @@ -1512,6 +1543,7 @@ static void pagetypeinfo_showfree_print(
> }
> seq_putc(m, '\n');
> }
> + mark_vmstat_dirty();

Why does a function which just dumps information via /proc/pagetypeinfo
make vmstats dirty?

Thanks,

tglx