From d5b6f6a3610b05e6712cb9c61a85a6dff16e91cf Mon Sep 17 00:00:00 2001
From: Oscar Salvador <osalvador@suse.de>
Date: Fri, 17 Aug 2018 15:46:18 -0700
Subject: [PATCH] mm/memory_hotplug.c: call register_mem_sect_under_node()
When hotplugging memory, it is possible that two calls are being made to
register_mem_sect_under_node().
One comes from __add_section()->hotplug_memory_register() and the other
from add_memory_resource()->link_mem_sections() if we had to register a
new node.
In case we had to register a new node, hotplug_memory_register() will
only handle/allocate the memory_block's since
register_mem_sect_under_node() will return right away because the node
it is not online yet.
I think it is better if we leave hotplug_memory_register() to
handle/allocate only memory_block's and make link_mem_sections() to call
register_mem_sect_under_node().
So this patch removes the call to register_mem_sect_under_node() from
hotplug_memory_register(), and moves the call to link_mem_sections() out
of the condition, so it will always be called. In this way we only have
one place where the memory sections are registered.
Link: http://lkml.kernel.org/r/20180622111839.10071-3-osalvador@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/base/memory.c | 2 --
mm/memory_hotplug.c | 32 +++++++++++---------------------
2 files changed, 11 insertions(+), 23 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index f5e560188a189..c8a1cb0b61361 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -736,8 +736,6 @@ int hotplug_memory_register(int nid, struct mem_section *section)
mem->section_count++;
}
- if (mem->section_count == sections_per_block)
- ret = register_mem_sect_under_node(mem, nid, false);
out:
mutex_unlock(&mem_sysfs_mutex);
return ret;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 504ba120bdfc7..e2ed64b994e5b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1123,6 +1123,7 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
u64 start, size;
bool new_node = false;
int ret;
+ unsigned long start_pfn, nr_pages;
start = res->start;
size = resource_size(res);
@@ -1151,34 +1152,23 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
if (ret < 0)
goto error;
- /* we online node here. we can't roll back from here. */
- node_set_online(nid);
-
if (new_node) {
- unsigned long start_pfn = start >> PAGE_SHIFT;
- unsigned long nr_pages = size >> PAGE_SHIFT;
-
- ret = __register_one_node(nid);
- if (ret)
- goto register_fail;
-
- /*
- * link memory sections under this node. This is already
- * done when creatig memory section in register_new_memory
- * but that depends to have the node registered so offline
- * nodes have to go through register_node.
- * TODO clean up this mess.
- */
- ret = link_mem_sections(nid, start_pfn, nr_pages, false);
-register_fail:
- /*
- * If sysfs file of new node can't create, cpu on the node
+ /* If sysfs file of new node can't be created, cpu on the node
* can't be hot-added. There is no rollback way now.
* So, check by BUG_ON() to catch it reluctantly..
+ * We online node here. We can't roll back from here.
*/
+ node_set_online(nid);
+ ret = __register_one_node(nid);
BUG_ON(ret);
}
+ /* link memory sections under this node.*/
+ start_pfn = start >> PAGE_SHIFT;
+ nr_pages = size >> PAGE_SHIFT;
+ ret = link_mem_sections(nid, start_pfn, nr_pages, false);
+ BUG_ON(ret);
+
/* create new memmap entry */
firmware_map_add_hotplug(start, start + size, "System RAM");