Messages in this thread | | | Date | Tue, 20 Nov 2012 14:29:28 -0800 | From | Andrew Morton <> | Subject | Re: [PART4 Patch v2 2/2] memory_hotplug: allow online/offline memory to result movable node |
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On Fri, 16 Nov 2012 19:58:10 +0800 Wen Congyang <wency@cn.fujitsu.com> wrote:
> From: Lai Jiangshan <laijs@cn.fujitsu.com> > > Now, memory management can handle movable node or nodes which don't have > any normal memory, so we can dynamic configure and add movable node by: > online a ZONE_MOVABLE memory from a previous offline node > offline the last normal memory which result a non-normal-memory-node > > movable-node is very important for power-saving, > hardware partitioning and high-available-system(hardware fault management). > > ... > > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -589,11 +589,19 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, > return 0; > } > > +#ifdef CONFIG_MOVABLE_NODE > +/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
The comment is hard to understand. Should it read "When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have normal memory"?
> +static bool can_online_high_movable(struct zone *zone) > +{ > + return true; > +} > +#else /* #ifdef CONFIG_MOVABLE_NODE */ > /* ensure every online node has NORMAL memory */ > static bool can_online_high_movable(struct zone *zone) > { > return node_state(zone_to_nid(zone), N_NORMAL_MEMORY); > } > +#endif /* #ifdef CONFIG_MOVABLE_NODE */ > > /* check which state of node_states will be changed when online memory */ > static void node_states_check_changes_online(unsigned long nr_pages, > @@ -1097,6 +1105,13 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) > return offlined; > } > > +#ifdef CONFIG_MOVABLE_NODE > +/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
Ditto, after replacing "online" with offlining".
> +static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) > +{ > + return true; > +} > +#else /* #ifdef CONFIG_MOVABLE_NODE */ > /* ensure the node has NORMAL memory if it is still online */ > static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) > { > @@ -1120,6 +1135,7 @@ static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) > */ > return present_pages == 0; > } > +#endif /* #ifdef CONFIG_MOVABLE_NODE */
Please, spend more time over the accuracy and completeness of the changelog and comments? That will result in better and more maintainable code. And it results in *much* more effective code reviewing.
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