Messages in this thread Patch in this message | | | Date | Tue, 21 May 2013 14:37:53 +0800 | From | Tang Chen <> | Subject | Re: [PATCH 2/2 v2, RFC] Driver core: Introduce offline/online callbacks for memory blocks |
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Hi Rafael,
Please see below.
On 05/04/2013 07:21 PM, Rafael J. Wysocki wrote: ...... > static BLOCKING_NOTIFIER_HEAD(memory_chain); > @@ -278,33 +283,64 @@ static int __memory_block_change_state(s > { > int ret = 0; > > - if (mem->state != from_state_req) { > - ret = -EINVAL; > - goto out; > - } > + if (mem->state != from_state_req) > + return -EINVAL; > > if (to_state == MEM_OFFLINE) > mem->state = MEM_GOING_OFFLINE; > > ret = memory_block_action(mem->start_section_nr, to_state, online_type); > - > if (ret) { > mem->state = from_state_req; > - goto out; > + } else { > + mem->state = to_state; > + if (to_state == MEM_ONLINE) > + mem->last_online = online_type;
Why do we need to remember last online type ?
And as far as I know, we can obtain which zone a page was in last time it was onlined by check page->flags, just like online_pages() does. If we use online_kernel or online_movable, the zone boundary will be recalculated. So we don't need to remember the last online type.
Seeing from your patch, I guess memory_subsys_online() can only handle online and offline. So mem->last_online is used to remember what user has done through the original way to trigger memory hot-remove, right ? And when user does it in this new way, it just does the same thing as user does last time.
But I still think we don't need to remember it because if finally you call online_pages(), it just does the same thing as last time by default.
online_pages() { ...... if (online_type == ONLINE_KERNEL ......
if (online_type == ONLINE_MOVABLE......
zone = page_zone(pfn_to_page(pfn));
/* Here, the page will be put into the zone which it belong to last time. */
...... }
I just thought of it. Maybe I missed something in your design. Please tell me if I'm wrong.
Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
Thanks. :)
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