On Wed, Jun 08, 2011 at 05:45:05PM +0900, KAMEZAWA Hiroyuki wrote:
> @@ -196,7 +195,11 @@ static int __meminit init_section_page_cgroup(unsigned long pfn)
> pc = base + index;
> init_page_cgroup(pc, nr);
> }
> -
> + /*
> + * Even if passed 'pfn' is not aligned to section, we need to align
> + * it to section boundary because of SPARSEMEM pfn calculation.
> + */
> + pfn = pfn & ~(PAGES_PER_SECTION - 1);
PAGE_SECTION_MASK?
> section->page_cgroup = base - pfn;
> total_usage += table_size;
> return 0;
> @@ -228,7 +231,7 @@ int __meminit online_page_cgroup(unsigned long start_pfn,
> for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
> if (!pfn_present(pfn))
> continue;
> - fail = init_section_page_cgroup(pfn);
> + fail = init_section_page_cgroup(pfn, nid);
AFAICS, nid can be -1 in the hotplug callbacks when there is a new
section added to a node that already has memory, and then the
allocation will fall back to numa_node_id().
So I think we either need to trust start_pfn has valid mem map backing
it (ARM has no memory hotplug support) and use pfn_to_nid(start_pfn),
or find another way to the right node, no?
> @@ -285,14 +288,36 @@ void __init page_cgroup_init(void)
> {
> unsigned long pfn;
> int fail = 0;
> + int nid;
>
> if (mem_cgroup_disabled())
> return;
>
> - for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
> - if (!pfn_present(pfn))
> - continue;
> - fail = init_section_page_cgroup(pfn);
> + for_each_node_state(nid, N_HIGH_MEMORY) {
> + unsigned long start_pfn, end_pfn;
> +
> + start_pfn = NODE_DATA(nid)->node_start_pfn;
> + end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
> + /*
> + * Because we cannot trust page->flags of page out of node
> + * boundary, we skip pfn < start_pfn.
> + */
> + for (pfn = start_pfn;
> + !fail && (pfn < end_pfn);
> + pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
If we don't bother to align the pfn on the first iteration, I don't
think we should for subsequent iterations. init_section_page_cgroup()
has to be able to cope anyway. How about
pfn += PAGES_PER_SECTION
instead?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>