Re: [PATCH 7/8] memory-hotplug: enable memory hotplug to handle hugepage

From: Hillf Danton
Date: Sat Jul 20 2013 - 06:04:41 EST


On Fri, Jul 19, 2013 at 10:39 PM, Naoya Horiguchi
<n-horiguchi@xxxxxxxxxxxxx> wrote:
> On Fri, Jul 19, 2013 at 01:40:38PM +0800, Hillf Danton wrote:
>> On Fri, Jul 19, 2013 at 5:34 AM, Naoya Horiguchi
>> <n-horiguchi@xxxxxxxxxxxxx> wrote:
>> > @@ -518,9 +519,11 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
>> > {
>> > struct page *page;
>> >
>> > - if (list_empty(&h->hugepage_freelists[nid]))
>> > + list_for_each_entry(page, &h->hugepage_freelists[nid], lru)
>> > + if (!is_migrate_isolate_page(page))
>> > + break;
>> > + if (&h->hugepage_freelists[nid] == &page->lru)
>>
>> For what is this check?
>
> This check returns true unless a non-isolated free hugepage is found.
> In "not found" case page points to h->hugepage_freelists, so without
> this check successive code doesn't work fine.
>
Thanks for your explanation, and looks another local variable
struct page *found for easing reader.

Good weekend
Hillf
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