On 2012-12-6 9:26, Tang Chen wrote:

On 12/05/2012 11:43 PM, Jiang Liu wrote:

quoted

If we make "movablecore_map" take precedence over "movablecore/kernelcore",
the logic could be simplified. I think it's not so attractive to support
both "movablecore_map" and "movablecore/kernelcore" at the same time.

Hi Liu,

Thanks for you advice. :)

Memory hotplug needs different support on different hardware. We are
trying to figure out a way to satisfy as many users as we can.
Since it is a little difficult, it may take sometime. :)

But I still think we need a boot option to support it. Just a metter of
how to make it easier to use. :)

Thanks. :)

quoted

On 11/23/2012 06:44 PM, Tang Chen wrote:

quoted

If kernelcore or movablecore is specified at the same time
with movablecore_map, movablecore_map will have higher
priority to be satisfied.
This patch will make find_zone_movable_pfns_for_nodes()
calculate zone_movable_pfn[] with the limit from
zone_movable_limit[].

Signed-off-by: Tang Chen<redacted>
Reviewed-by: Wen Congyang<redacted>
Reviewed-by: Lai Jiangshan<redacted>
Tested-by: Lin Feng<redacted>
---
  mm/page_alloc.c |   35 +++++++++++++++++++++++++++++++----
  1 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f23d76a..05bafbb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c

@@ -4800,12 +4800,25 @@ static void __init find_zone_movable_pfns_for_nodes(void)
          required_kernelcore = max(required_kernelcore, corepages);
      }

-    /* If kernelcore was not specified, there is no ZONE_MOVABLE */
-    if (!required_kernelcore)
+    /*
+     * No matter kernelcore/movablecore was limited or not, movable_zone
+     * should always be set to a usable zone index.
+     */
+    find_usable_zone_for_movable();
+
+    /*
+     * If neither kernelcore/movablecore nor movablecore_map is specified,
+     * there is no ZONE_MOVABLE. But if movablecore_map is specified, the
+     * start pfn of ZONE_MOVABLE has been stored in zone_movable_limit[].
+     */
+    if (!required_kernelcore) {
+        if (movablecore_map.nr_map)
+            memcpy(zone_movable_pfn, zone_movable_limit,
+                sizeof(zone_movable_pfn));
          goto out;
+    }

      /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
-    find_usable_zone_for_movable();
      usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];

  restart:

@@ -4833,10 +4846,24 @@ restart:
          for_each_mem_pfn_range(i, nid,&start_pfn,&end_pfn, NULL) {
              unsigned long size_pages;

+            /*
+             * Find more memory for kernelcore in
+             * [zone_movable_pfn[nid], zone_movable_limit[nid]).
+             */
              start_pfn = max(start_pfn, zone_movable_pfn[nid]);
              if (start_pfn>= end_pfn)
                  continue;

+            if (zone_movable_limit[nid]) {
+                end_pfn = min(end_pfn, zone_movable_limit[nid]);
+                /* No range left for kernelcore in this node */
+                if (start_pfn>= end_pfn) {
+                    zone_movable_pfn[nid] =
+                            zone_movable_limit[nid];
+                    break;
+                }
+            }

Hi Tang,
	I just to remove the above logic, so the implementation will be greatly
simplified. Please refer to the attachment.
Regards!
Gerry

quoted

quoted

+
              /* Account for what is only usable for kernelcore */
              if (start_pfn<  usable_startpfn) {
                  unsigned long kernel_pages;

@@ -4896,12 +4923,12 @@ restart:
      if (usable_nodes&&  required_kernelcore>  usable_nodes)
          goto restart;

+out:
      /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
      for (nid = 0; nid<  MAX_NUMNODES; nid++)
          zone_movable_pfn[nid] =
              roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);

-out:
      /* restore the node_state */
      node_states[N_HIGH_MEMORY] = saved_node_state;
  }

.