Re: [PATCH v1 3/5] mm/memory_hotplug: check if sections are already online/offline

On 8/16/18 7:00 AM, David Hildenbrand wrote:

On 16.08.2018 12:47, Oscar Salvador wrote:

quoted

On Thu, Aug 16, 2018 at 12:06:26PM +0200, David Hildenbrand wrote:

quoted

+
+/* check if all mem sections are offline */
+bool mem_sections_offline(unsigned long pfn, unsigned long end_pfn)
+{
+	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+		unsigned long section_nr = pfn_to_section_nr(pfn);
+
+		if (WARN_ON(!valid_section_nr(section_nr)))
+			continue;
+		if (online_section_nr(section_nr))
+			return false;
+	}
+	return true;
+}

AFAICS pages_correctly_probed will catch this first.
pages_correctly_probed checks for the section to be:

- present
- valid
- !online

Right, I missed that function.

quoted

Maybe it makes sense to rename it, and write another pages_correctly_probed routine
for the offline case.

So all checks would stay in memory_block_action level, and we would not need
the mem_sections_offline/online stuff.

I am OK with that, but will wait for a patch to review.

Pavel