[PATCH v2 3/4] mm/memory_hotplug: Make register_mem_sect_under_node a cb of walk_memory_range

From: osalvador
Date: Fri Jun 22 2018 - 07:20:10 EST


From: Oscar Salvador <osalvador@xxxxxxx>

link_mem_sections() and walk_memory_range() share most of the code,
so we can use convert link_mem_sections() into a dummy function that calls
walk_memory_range() with a callback to register_mem_sect_under_node().

This patch converts register_mem_sect_under_node() in order to
match a walk_memory_range's callback, getting rid of the
check_nid argument and checking instead if the system is still
boothing, since we only have to check for the nid if the system
is in such state.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Suggested-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
drivers/base/node.c | 44 ++++++--------------------------------------
include/linux/node.h | 12 +++++++-----
mm/memory_hotplug.c | 5 +----
3 files changed, 14 insertions(+), 47 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index a5e821d09656..845d5523812b 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -399,10 +399,9 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
}

/* register memory section under specified node if it spans that node */
-int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
- bool check_nid)
+int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
{
- int ret;
+ int ret, nid = *(int *)arg;
unsigned long pfn, sect_start_pfn, sect_end_pfn;

if (!mem_blk)
@@ -433,7 +432,7 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
* case, during hotplug we know that all pages in the memory
* block belong to the same node.
*/
- if (check_nid) {
+ if (system_state == SYSTEM_BOOTING) {
page_nid = get_nid_for_pfn(pfn);
if (page_nid < 0)
continue;
@@ -490,41 +489,10 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
return 0;
}

-int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages,
- bool check_nid)
+int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)
{
- unsigned long end_pfn = start_pfn + nr_pages;
- unsigned long pfn;
- struct memory_block *mem_blk = NULL;
- int err = 0;
-
- for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
- unsigned long section_nr = pfn_to_section_nr(pfn);
- struct mem_section *mem_sect;
- int ret;
-
- if (!present_section_nr(section_nr))
- continue;
- mem_sect = __nr_to_section(section_nr);
-
- /* same memblock ? */
- if (mem_blk)
- if ((section_nr >= mem_blk->start_section_nr) &&
- (section_nr <= mem_blk->end_section_nr))
- continue;
-
- mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
-
- ret = register_mem_sect_under_node(mem_blk, nid, check_nid);
- if (!err)
- err = ret;
-
- /* discard ref obtained in find_memory_block() */
- }
-
- if (mem_blk)
- kobject_put(&mem_blk->dev.kobj);
- return err;
+ return walk_memory_range(start_pfn, end_pfn, (void *)&nid,
+ register_mem_sect_under_node);
}

#ifdef CONFIG_HUGETLBFS
diff --git a/include/linux/node.h b/include/linux/node.h
index 6d336e38d155..257bb3d6d014 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -33,10 +33,10 @@ typedef void (*node_registration_func_t)(struct node *);

#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_NUMA)
extern int link_mem_sections(int nid, unsigned long start_pfn,
- unsigned long nr_pages, bool check_nid);
+ unsigned long end_pfn);
#else
static inline int link_mem_sections(int nid, unsigned long start_pfn,
- unsigned long nr_pages, bool check_nid)
+ unsigned long end_pfn)
{
return 0;
}
@@ -54,12 +54,14 @@ static inline int register_one_node(int nid)

if (node_online(nid)) {
struct pglist_data *pgdat = NODE_DATA(nid);
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;

error = __register_one_node(nid);
if (error)
return error;
/* link memory sections under this node */
- error = link_mem_sections(nid, pgdat->node_start_pfn, pgdat->node_spanned_pages, true);
+ error = link_mem_sections(nid, start_pfn, end_pfn);
}

return error;
@@ -69,7 +71,7 @@ extern void unregister_one_node(int nid);
extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
extern int register_mem_sect_under_node(struct memory_block *mem_blk,
- int nid, bool check_nid);
+ void *arg);
extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
unsigned long phys_index);

@@ -99,7 +101,7 @@ static inline int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
return 0;
}
static inline int register_mem_sect_under_node(struct memory_block *mem_blk,
- int nid, bool check_nid)
+ void *arg)
{
return 0;
}
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e2ed64b994e5..4eb6e824a80c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1123,7 +1123,6 @@ 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);
@@ -1164,9 +1163,7 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
}

/* 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);
+ ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1));
BUG_ON(ret);

/* create new memmap entry */
--
2.13.6