Merge branch 'dynamic_sg' into rdma.git for-next

From Maor Gottlieb says:

====================
This series extends __sg_alloc_table_from_pages to allow chaining of new
pages to an already initialized SG table.

This allows for drivers to utilize the optimization of merging contiguous
pages without a need to pre allocate all the pages and hold them in a very
large temporary buffer prior to the call to SG table initialization.

The last patch changes the Infiniband core to use the new API. It removes
duplicate functionality from the code and benefits from the optimization
of allocating dynamic SG table from pages.

In huge pages system of 2MB page size, without this change, the SG table
would contain x512 SG entries.
====================

* branch 'dynamic_sg':
  RDMA/umem: Move to allocate SG table from pages
  lib/scatterlist: Add support in dynamic allocation of SG table from pages
  tools/testing/scatterlist: Show errors in human readable form
  tools/testing/scatterlist: Rejuvenate bit-rotten test

1 files changed, 55 insertions, 30 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 508b80f6329b..50af16e68d98 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -761,14 +761,36 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
 	return pfn_to_nid(pfn);
 }
 
+static int do_register_memory_block_under_node(int nid,
+					       struct memory_block *mem_blk)
+{
+	int ret;
+
+	/*
+	 * If this memory block spans multiple nodes, we only indicate
+	 * the last processed node.
+	 */
+	mem_blk->nid = nid;
+
+	ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
+				       &mem_blk->dev.kobj,
+				       kobject_name(&mem_blk->dev.kobj));
+	if (ret)
+		return ret;
+
+	return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
+				&node_devices[nid]->dev.kobj,
+				kobject_name(&node_devices[nid]->dev.kobj));
+}
+
 /* register memory section under specified node if it spans that node */
-static int register_mem_sect_under_node(struct memory_block *mem_blk,
-					 void *arg)
+static int register_mem_block_under_node_early(struct memory_block *mem_blk,
+					       void *arg)
 {
 	unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
 	unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
 	unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
-	int ret, nid = *(int *)arg;
+	int nid = *(int *)arg;
 	unsigned long pfn;
 
 	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
@@ -785,39 +807,34 @@ static int register_mem_sect_under_node(struct memory_block *mem_blk,
 		}
 
 		/*
-		 * We need to check if page belongs to nid only for the boot
-		 * case, during hotplug we know that all pages in the memory
-		 * block belong to the same node.
-		 */
-		if (system_state == SYSTEM_BOOTING) {
-			page_nid = get_nid_for_pfn(pfn);
-			if (page_nid < 0)
-				continue;
-			if (page_nid != nid)
-				continue;
-		}
-
-		/*
-		 * If this memory block spans multiple nodes, we only indicate
-		 * the last processed node.
+		 * We need to check if page belongs to nid only at the boot
+		 * case because node's ranges can be interleaved.
 		 */
-		mem_blk->nid = nid;
-
-		ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
-					&mem_blk->dev.kobj,
-					kobject_name(&mem_blk->dev.kobj));
-		if (ret)
-			return ret;
+		page_nid = get_nid_for_pfn(pfn);
+		if (page_nid < 0)
+			continue;
+		if (page_nid != nid)
+			continue;
 
-		return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
-				&node_devices[nid]->dev.kobj,
-				kobject_name(&node_devices[nid]->dev.kobj));
+		return do_register_memory_block_under_node(nid, mem_blk);
 	}
 	/* mem section does not span the specified node */
 	return 0;
 }
 
 /*
+ * During hotplug we know that all pages in the memory block belong to the same
+ * node.
+ */
+static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
+						 void *arg)
+{
+	int nid = *(int *)arg;
+
+	return do_register_memory_block_under_node(nid, mem_blk);
+}
+
+/*
  * Unregister a memory block device under the node it spans. Memory blocks
  * with multiple nodes cannot be offlined and therefore also never be removed.
  */
@@ -832,11 +849,19 @@ void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
 			  kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
 }
 
-int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)
+int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn,
+		      enum meminit_context context)
 {
+	walk_memory_blocks_func_t func;
+
+	if (context == MEMINIT_HOTPLUG)
+		func = register_mem_block_under_node_hotplug;
+	else
+		func = register_mem_block_under_node_early;
+
 	return walk_memory_blocks(PFN_PHYS(start_pfn),
 				  PFN_PHYS(end_pfn - start_pfn), (void *)&nid,
-				  register_mem_sect_under_node);
+				  func);
 }
 
 #ifdef CONFIG_HUGETLBFS