From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f70.google.com (mail-lf0-f70.google.com [209.85.215.70]) by kanga.kvack.org (Postfix) with ESMTP id 63B766B007E for ; Fri, 10 Jun 2016 12:39:33 -0400 (EDT) Received: by mail-lf0-f70.google.com with SMTP id u74so32992643lff.0 for ; Fri, 10 Jun 2016 09:39:33 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id y195si33845362wme.63.2016.06.10.09.39.31 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 10 Jun 2016 09:39:32 -0700 (PDT) Subject: Re: [PATCH 02/27] mm, vmscan: Move lru_lock to the node References: <1465495483-11855-1-git-send-email-mgorman@techsingularity.net> <1465495483-11855-3-git-send-email-mgorman@techsingularity.net> From: Vlastimil Babka Message-ID: <575AED3E.3090705@suse.cz> Date: Fri, 10 Jun 2016 18:39:26 +0200 MIME-Version: 1.0 In-Reply-To: <1465495483-11855-3-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Andrew Morton , Linux-MM Cc: Rik van Riel , Johannes Weiner , LKML , Peter Zijlstra On 06/09/2016 08:04 PM, Mel Gorman wrote: > Node-based reclaim requires node-based LRUs and locking. This is a > preparation patch that just moves the lru_lock to the node so later patches > are easier to review. It is a mechanical change but note this patch makes > contention worse because the LRU lock is hotter and direct reclaim and kswapd > can contend on the same lock even when reclaiming from different zones. > > Signed-off-by: Mel Gorman > Acked-by: Johannes Weiner Acked-by: Vlastimil Babka One thing... > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 9d71af25acf9..1e0ad06c33bd 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5944,10 +5944,10 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat) > zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; > #endif > zone->name = zone_names[j]; > + zone->zone_pgdat = pgdat; > spin_lock_init(&zone->lock); > - spin_lock_init(&zone->lru_lock); > + spin_lock_init(zone_lru_lock(zone)); This means the same lock will be inited MAX_NR_ZONES times. Peterz told me it's valid but weird. Probably better to do it just once, in case lockdep/lock debugging gains some checks for that? > zone_seqlock_init(zone); > - zone->zone_pgdat = pgdat; > zone_pcp_init(zone); > > /* For bootup, initialized properly in watermark setup */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org