From: Oscar Salvador <osalvador@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
Michal Hocko <mhocko@kernel.org>,
Wei Yang <richard.weiyang@gmail.com>,
Miaohe Lin <linmiaohe@huawei.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Oscar Salvador <osalvador@suse.de>
Subject: [PATCH 3/3] mm/memory_hotplug: Refactor hotadd_init_pgdat and try_online_node
Date: Mon, 7 Mar 2022 16:07:25 +0100 [thread overview]
Message-ID: <20220307150725.6810-4-osalvador@suse.de> (raw)
In-Reply-To: <20220307150725.6810-1-osalvador@suse.de>
Since we pre-allocate all nodes now, hotadd_init_pgdat() does
not need to return a pgdat struct, as that was meant for
__try_online_node() to check whether the node was succesfully
allocated.
Also get rid of the __ref as all functions hotadd_init_pgdat()
calls fall within the same section.
Also try to make more clear the return codes from __try_online_node().
__try_online_node() can return either 0, 1 or -errno (the latter not really
as the BUG_ON() would catch it before we return) but depending on the caller
that has different meanings.
For add_memory_resource(), when __try_online_node() returns non-zero,
it means that the node was already allocated and it does not need to bring
it up. It is fine not to check for -errno values because we do not
get to call register_one_node() when !set_node_online.
For those who call try_online_node(), so set_node_online is true, a value
other than zero means a failure (e.g: cpu_up() or find_and_online_cpu_nid()).
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
mm/memory_hotplug.c | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 07cece9e22e4..5c92ac81a399 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1161,8 +1161,7 @@ static void reset_node_present_pages(pg_data_t *pgdat)
pgdat->node_present_pages = 0;
}
-/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
-static pg_data_t __ref *hotadd_init_pgdat(int nid)
+static void hotadd_init_pgdat(int nid)
{
struct pglist_data *pgdat = NODE_DATA(nid);
@@ -1182,8 +1181,6 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
* to access not-initialized zonelist, build here.
*/
build_all_zonelists(pgdat);
-
- return pgdat;
}
/*
@@ -1193,31 +1190,27 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
* called by cpu_up() to online a node without onlined memory.
*
* Returns:
- * 1 -> a new node has been allocated
- * 0 -> the node is already online
- * -ENOMEM -> the node could not be allocated
+ * 1 -> The node has been initialized.
+ * 0 -> Either the node was already online, or we succesfully registered a new
+ * one.
+ * -errno -> register_one_node() failed.
*/
static int __try_online_node(int nid, bool set_node_online)
{
- pg_data_t *pgdat;
- int ret = 1;
+ int ret;
if (node_online(nid))
return 0;
- pgdat = hotadd_init_pgdat(nid);
- if (!pgdat) {
- pr_err("Cannot online node %d due to NULL pgdat\n", nid);
- ret = -ENOMEM;
- goto out;
- }
+ hotadd_init_pgdat(nid);
+
+ if (!set_node_online)
+ return 1;
+
+ node_set_online(nid);
+ ret = register_one_node(nid);
+ BUG_ON(ret);
- if (set_node_online) {
- node_set_online(nid);
- ret = register_one_node(nid);
- BUG_ON(ret);
- }
-out:
return ret;
}
--
2.34.1
next prev parent reply other threads:[~2022-03-07 15:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-07 15:07 [PATCH 0/3] A minor hotplug refactoring Oscar Salvador
2022-03-07 15:07 ` [PATCH 1/3] mm/page_alloc: Do not calculate node's total pages and memmap pages when empty Oscar Salvador
2022-04-28 12:13 ` David Hildenbrand
2022-05-05 9:09 ` Oscar Salvador
2022-03-07 15:07 ` [PATCH 2/3] mm/memory_hotplug: Reset node's state when empty during offline Oscar Salvador
2022-04-28 12:30 ` David Hildenbrand
2022-05-05 10:37 ` Oscar Salvador
2022-03-07 15:07 ` Oscar Salvador [this message]
2022-04-28 12:35 ` [PATCH 3/3] mm/memory_hotplug: Refactor hotadd_init_pgdat and try_online_node David Hildenbrand
2022-05-05 9:17 ` Oscar Salvador
2022-04-27 21:05 ` [PATCH 0/3] A minor hotplug refactoring Andrew Morton
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