Re: [PATCH -mm] mm: Fix memory hotplug + sparsemem build.

Yasunori Goto
2007-09-14T02:02:43Z

> On Tue, 11 Sep 2007 18:37:12 +0900 Yasunori Goto <y-goto@jp.fujitsu.com> wrote:
>
> >
> > > > + if (onlined_pages){
> > >
> > > Nit, needs a space there before the '{'.
> >
> > Ah, Ok. I attached fixed patch in this mail.
> >
> > > 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@shadowen.org>
> >
> > Thanks for your explanation.
> > You mentioned all of my intention correctly. :-)
> >
> >
> > ----
> >
> > 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 <y-goto@jp.fujitsu.com>
> > Signed-off-by: Paul Mundt <lethal@linux-sh.org>
> > Acked-by: Andy Whitcroft <apw@shadowen.org>
> >
> >
> > ---
> > 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) {
> > + 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 */
> >
>
> OK, we're getting into a mess here. This patch fixes
> update-n_high_memory-node-state-for-memory-hotadd.patch, but which patch
> does update-n_high_memory-node-state-for-memory-hotadd.patch fix?
>
> At present I just whacked
> update-n_high_memory-node-state-for-memory-hotadd.patch at the end of
> everything, but that was lazy of me and it ends up making a mess.

It is enough. No more patch is necessary for these issues.
I already fixed about Andy-san's comment. :-)

Thanks.
--
Yasunori Goto