From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753513AbcGDXte (ORCPT ); Mon, 4 Jul 2016 19:49:34 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:36568 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920AbcGDXtc (ORCPT ); Mon, 4 Jul 2016 19:49:32 -0400 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 165.244.98.204 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Tue, 5 Jul 2016 08:50:18 +0900 From: Minchan Kim To: Mel Gorman CC: Andrew Morton , Linux-MM , Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML Subject: Re: [PATCH 01/31] mm, vmstat: add infrastructure for per-node vmstats Message-ID: <20160704235018.GA26749@bbox> References: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> <1467403299-25786-2-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 In-Reply-To: <1467403299-25786-2-git-send-email-mgorman@techsingularity.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB08/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/05 08:49:29, Serialize by Router on LGEKRMHUB08/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/05 08:49:29, Serialize complete at 2016/07/05 08:49:29 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 01, 2016 at 09:01:09PM +0100, Mel Gorman wrote: > VM statistic counters for reclaim decisions are zone-based. If the kernel > is to reclaim on a per-node basis then we need to track per-node > statistics but there is no infrastructure for that. The most notable > change is that the old node_page_state is renamed to > sum_zone_node_page_state. The new node_page_state takes a pglist_data and > uses per-node stats but none exist yet. There is some renaming such as > vm_stat to vm_zone_stat and the addition of vm_node_stat and the renaming > of mod_state to mod_zone_state. Otherwise, this is mostly a mechanical > patch with no functional change. There is a lot of similarity between the > node and zone helpers which is unfortunate but there was no obvious way of > reusing the code and maintaining type safety. > > Signed-off-by: Mel Gorman > Acked-by: Johannes Weiner > Acked-by: Vlastimil Babka > --- > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 7997f52935c9..90b0737ee4be 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -86,8 +86,10 @@ void vm_events_fold_cpu(int cpu) > * > * vm_stat contains the global counters > */ > -atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; > -EXPORT_SYMBOL(vm_stat); > +atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; > +atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp; > +EXPORT_SYMBOL(vm_zone_stat); > +EXPORT_SYMBOL(vm_node_stat); > > #ifdef CONFIG_SMP > > @@ -172,13 +174,17 @@ void refresh_zone_stat_thresholds(void) > int threshold; > > for_each_populated_zone(zone) { > + struct pglist_data *pgdat = zone->zone_pgdat; > unsigned long max_drift, tolerate_drift; > > threshold = calculate_normal_threshold(zone); > > - for_each_online_cpu(cpu) > + for_each_online_cpu(cpu) { > per_cpu_ptr(zone->pageset, cpu)->stat_threshold > = threshold; > + per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold > + = threshold; > + } I didn't see other patches yet so it might fix it then. per_cpu_nodestats is per node not zone but it use per-zone threshold and even overwritten by next zones. I don't think it's not intended.