Message-ID: <93b293341866a4366b2f2a614f8742ca94ff4e3c.camel@linux.intel.com>
Subject: Re: [PATCH v7 13/13] vmstat: add pcp remote node draining via
 cpu_vm_stats_fold
From:   Tim Chen <tim.c.chen@linux.intel.com>
To:     Marcelo Tosatti <mtosatti@redhat.com>,
        Christoph Lameter <cl@linux.com>
Cc:     Aaron Tomlin <atomlin@atomlin.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Russell King <linux@armlinux.org.uk>,
        Huacai Chen <chenhuacai@kernel.org>,
        Heiko Carstens <hca@linux.ibm.com>, x86@kernel.org,
        Vlastimil Babka <vbabka@suse.cz>,
        Michal Hocko <mhocko@suse.com>
Date:   Mon, 20 Mar 2023 13:43:09 -0700
In-Reply-To: <20230320180745.858515310@redhat.com>
References: <20230320180332.102837832@redhat.com>
         <20230320180745.858515310@redhat.com>
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On Mon, 2023-03-20 at 15:03 -0300, Marcelo Tosatti wrote:
>=20
> +
> +		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) =3D=3D cpu_to_node(cpu)) {
> +				pcp->expire =3D 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 refre=
sh_cpu_vm_stats().
Is it possible to consolidate to avoid replicating the logic across two fun=
ctions?

Tim=20