Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933578AbXIKJPq (ORCPT ); Tue, 11 Sep 2007 05:15:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759909AbXIKJPi (ORCPT ); Tue, 11 Sep 2007 05:15:38 -0400 Received: from hellhawk.shadowen.org ([80.68.90.175]:3888 "EHLO hellhawk.shadowen.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756853AbXIKJPh (ORCPT ); Tue, 11 Sep 2007 05:15:37 -0400 Date: Tue, 11 Sep 2007 10:15:16 +0100 From: Andy Whitcroft To: Yasunori Goto Cc: Paul Mundt , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH -mm] mm: Fix memory hotplug + sparsemem build. Message-ID: <20070911091516.GE6288@shadowen.org> References: <20070911072507.GB19260@linux-sh.org> <20070911170921.F137.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070911170921.F137.Y-GOTO@jp.fujitsu.com> User-Agent: Mutt/1.5.13 (2006-08-11) X-SPF-Guess: neutral Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2517 Lines: 80 On Tue, Sep 11, 2007 at 05:18:01PM +0900, Yasunori Goto wrote: > > if (onlined_pages) > > - node_set_state(zone->node, N_HIGH_MEMORY); > > + node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); > > > > setup_per_zone_pages_min(); > > Thanks Paul-san. > > I also have another issue around here. > (Kswapd doesn't run on memory less node now. It should run when > the node has memory.) > > I would like to merge them like following if you don't mind. > > > Bye. > > --- > > Fix kswapd doesn't run when memory is added on memory-less-node. > Fix compile error of zone->node when CONFIG_NUMA is off. > > Signed-off-by: Yasunori Goto > Signed-off-by: Paul Mundt > > > --- > mm/memory_hotplug.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > Index: current/mm/memory_hotplug.c > =================================================================== > --- current.orig/mm/memory_hotplug.c 2007-09-07 18:08:07.000000000 +0900 > +++ current/mm/memory_hotplug.c 2007-09-11 17:29:19.000000000 +0900 > @@ -211,10 +211,12 @@ int online_pages(unsigned long pfn, unsi > online_pages_range); > zone->present_pages += onlined_pages; > zone->zone_pgdat->node_present_pages += onlined_pages; > - if (onlined_pages) > - node_set_state(zone->node, N_HIGH_MEMORY); > > setup_per_zone_pages_min(); > + if (onlined_pages){ Nit, needs a space there before the '{'. > + kswapd_run(zone_to_nid(zone)); > + node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); > + } > > if (need_zonelists_rebuild) > build_all_zonelists(); > @@ -269,9 +271,6 @@ int add_memory(int nid, u64 start, u64 s > if (!pgdat) > return -ENOMEM; > new_pgdat = 1; > - ret = kswapd_run(nid); > - if (ret) > - goto error; > } > > /* call arch's memory hotadd */ The problem as I see it is that when we boot the system we start a kswapd on all nodes with memory. If the hot-add adds memory to a pre-existing node with no memory we will not start one and we end up with a node with memory and no kswapd. Bad. As kswapd_run is a no-op when a kswapd already exists this seems a safe way to fix that. Paul's ->zone conversion is obviously correct also. Acked-by: Andy Whitcroft -apw - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/