Re: [PATCH v7 13/13] vmstat: add pcp remote node draining via cpu_vm_stats_fold

[Tim Chen]

On Mon, 2023-03-20 at 15:03 -0300, Marcelo Tosatti wrote:
> 
> +
> +		if (do_pagesets) {
> +			cond_resched();
> +			/*
> +			 * Deal with draining the remote pageset of a
> +			 * processor
> +			 *
> +			 * Check if there are pages remaining in this pageset
> +			 * if not then there is nothing to expire.
> +			 */
> +			if (!pcp->expire || !pcp->count)
> +				continue;refresh_cpu_vm_stats
> +
> +			/*
> +			 * We never drain zones local to this processor.
> +			 */
> +			if (zone_to_nid(zone) == cpu_to_node(cpu)) {
> +				pcp->expire = 0;
> +				continue;
> +			}
> +
> +			WARN_ON(pcp->expire < 0);
> +			/*
> +			 * pcp->expire is only accessed from vmstat_shepherd context,
> +			 * therefore no locking is required.
> +			 */
> +			if (--pcp->expire)
> +				continue;
> +
> +			if (pcp->count)
> +				drain_zone_pages(zone, pcp);
> +		}

This logic is the same to that for the do_pagesets portion of code in refresh_cpu_vm_stats().
Is it possible to consolidate to avoid replicating the logic across two functions?

Tim