Re: [Bugme-new] [Bug 36192] New: Kernel panic when boot the 2.6.39+ kernel based off of 2.6.32 kernel
From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2011-06-08 10:15:28
On Wed, Jun 08, 2011 at 05:45:05PM +0900, KAMEZAWA Hiroyuki wrote:
quoted hunk ↗ jump to hunk
@@ -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?
quoted hunk ↗ jump to hunk
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?
quoted hunk ↗ jump to hunk
@@ -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@kvack.org. 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@kvack.org"> email@kvack.org </a>