Because memory-less node's ->node_present_pages and its
zone's ->present_pages are all 0, the judgement before calling
node_set_state() to set N_MEMORY, N_HIGH_MEMORY, N_NORMAL_MEMORY for
node is enough to skip memory-less node. The 'continue;' statement
inside for_each_node() loop of free_area_init() is gilding the lily.
Here, remove the special handling to make memory-less node share the
same code flow as normal node.
And also rephrase the code comments above the 'continue' statement
and move them above above line 'if (pgdat->node_present_pages)'.
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
v1->v2:
- As Mike suggested, the old code comments above the 'continue'
statement is still useful for easier understanding code and system
behaviour. So rephrase and move them above line 'if
(pgdat->node_present_pages)'. Thanks to Mike.
mm/mm_init.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 2016ca8031e9..32ede966e609 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1834,28 +1834,23 @@ void __init free_area_init(unsigned long *max_zone_pfn)
panic("Cannot allocate %zuB for node %d.\n",
sizeof(*pgdat), nid);
arch_refresh_nodedata(nid, pgdat);
- free_area_init_node(nid);
-
- /*
- * We do not want to confuse userspace by sysfs
- * files/directories for node without any memory
- * attached to it, so this node is not marked as
- * N_MEMORY and not marked online so that no sysfs
- * hierarchy will be created via register_one_node for
- * it. The pgdat will get fully initialized by
- * hotadd_init_pgdat() when memory is hotplugged into
- * this node.
- */
- continue;
}
pgdat = NODE_DATA(nid);
free_area_init_node(nid);
- /* Any memory on that node */
- if (pgdat->node_present_pages)
+ /*
+ * No sysfs hierarcy will be created via register_one_node()
+ *for memory-less node because here it's not marked as N_MEMORY
+ *and won't be set online later. The benefit is userspace
+ *program won't be confused by sysfs files/directories of
+ *memory-less node. The pgdat will get fully initialized by
+ *hotadd_init_pgdat() when memory is hotplugged into this node.
+ */
+ if (pgdat->node_present_pages) {
node_set_state(nid, N_MEMORY);
- check_for_memory(pgdat);
+ check_for_memory(pgdat);
+ }
}
calc_nr_kernel_pages();
--
2.41.0
