From: Huang Ying <ying.huang@intel.com>
To: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org,
Dave Hansen <dave.hansen@linux.intel.com>,
"Huang, Ying" <ying.huang@intel.com>,
Yang Shi <shy828301@gmail.com>, Michal Hocko <mhocko@suse.com>,
Wei Xu <weixugc@google.com>, David Rientjes <rientjes@google.com>,
Dan Williams <dan.j.williams@intel.com>,
David Hildenbrand <david@redhat.com>,
osalvador <osalvador@suse.de>
Subject: [PATCH -V8 01/10] mm/numa: node demotion data structure and lookup
Date: Fri, 18 Jun 2021 14:15:28 +0800 [thread overview]
Message-ID: <20210618061537.434999-2-ying.huang@intel.com> (raw)
In-Reply-To: <20210618061537.434999-1-ying.huang@intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
Prepare for the kernel to auto-migrate pages to other memory nodes
with a user defined node migration table. This allows creating single
migration target for each NUMA node to enable the kernel to do NUMA
page migrations instead of simply reclaiming colder pages. A node
with no target is a "terminal node", so reclaim acts normally there.
The migration target does not fundamentally _need_ to be a single node,
but this implementation starts there to limit complexity.
If you consider the migration path as a graph, cycles (loops) in the
graph are disallowed. This avoids wasting resources by constantly
migrating (A->B, B->A, A->B ...). The expectation is that cycles will
never be allowed.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: osalvador <osalvador@suse.de>
--
changes since 20200122:
* Make node_demotion[] __read_mostly
changes in July 2020:
- Remove loop from next_demotion_node() and get_online_mems().
This means that the node returned by next_demotion_node()
might now be offline, but the worst case is that the
allocation fails. That's fine since it is transient.
---
mm/migrate.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/mm/migrate.c b/mm/migrate.c
index b234c3f3acb7..6cab668132f9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1136,6 +1136,23 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
return rc;
}
+static int node_demotion[MAX_NUMNODES] __read_mostly =
+ {[0 ... MAX_NUMNODES - 1] = NUMA_NO_NODE};
+
+/**
+ * next_demotion_node() - Get the next node in the demotion path
+ * @node: The starting node to lookup the next node
+ *
+ * @returns: node id for next memory node in the demotion path hierarchy
+ * from @node; NUMA_NO_NODE if @node is terminal. This does not keep
+ * @node online or guarantee that it *continues* to be the next demotion
+ * target.
+ */
+int next_demotion_node(int node)
+{
+ return node_demotion[node];
+}
+
/*
* Obtain the lock on page, remove all ptes and migrate the page
* to the newly allocated page in newpage.
--
2.30.2
next prev parent reply other threads:[~2021-06-18 6:19 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-18 6:15 [PATCH -V8 00/10] Migrate Pages in lieu of discard Huang Ying
2021-06-18 6:15 ` Huang Ying [this message]
2021-06-18 6:15 ` [PATCH -V8 02/10] mm/numa: automatically generate node migration order Huang Ying
2021-06-18 15:14 ` Zi Yan
2021-06-19 8:18 ` Huang, Ying
2021-06-19 8:18 ` Huang, Ying
2021-06-21 14:50 ` Zi Yan
2021-06-22 1:14 ` Huang, Ying
2021-06-22 1:14 ` Huang, Ying
2021-06-22 12:13 ` Dave Hansen
2021-06-22 12:06 ` Dave Hansen
2021-06-22 12:48 ` Zi Yan
2021-06-21 19:51 ` Yang Shi
2021-06-21 19:51 ` Yang Shi
2021-06-22 0:55 ` Huang, Ying
2021-06-22 0:55 ` Huang, Ying
2021-06-21 19:53 ` Dave Hansen
2021-06-22 0:54 ` Huang, Ying
2021-06-22 0:54 ` Huang, Ying
2021-06-18 6:15 ` [PATCH -V8 03/10] mm/migrate: update node demotion order during on hotplug events Huang Ying
2021-06-18 6:15 ` [PATCH -V8 04/10] mm/migrate: make migrate_pages() return nr_succeeded Huang Ying
2021-06-18 7:53 ` Oscar Salvador
2021-06-18 8:15 ` Huang, Ying
2021-06-18 8:15 ` Huang, Ying
2021-06-18 6:15 ` [PATCH -V8 05/10] mm/migrate: demote pages during reclaim Huang Ying
2021-06-18 15:42 ` Zi Yan
2021-06-19 7:45 ` Huang, Ying
2021-06-19 7:45 ` Huang, Ying
2021-06-21 19:58 ` Yang Shi
2021-06-21 19:58 ` Yang Shi
2021-06-22 2:09 ` Huang, Ying
2021-06-22 2:09 ` Huang, Ying
2021-06-22 17:15 ` Yang Shi
2021-06-22 17:15 ` Yang Shi
2021-06-22 18:15 ` Zi Yan
2021-06-23 2:19 ` Huang, Ying
2021-06-23 2:19 ` Huang, Ying
2021-06-18 6:15 ` [PATCH -V8 06/10] mm/vmscan: add page demotion counter Huang Ying
2021-06-18 6:15 ` [PATCH -V8 07/10] mm/vmscan: add helper for querying ability to age anonymous pages Huang Ying
2021-06-18 15:45 ` Zi Yan
2021-06-19 2:33 ` Huang, Ying
2021-06-19 2:33 ` Huang, Ying
2021-06-18 6:15 ` [PATCH -V8 08/10] mm/vmscan: Consider anonymous pages without swap Huang Ying
2021-06-18 6:15 ` [PATCH -V8 09/10] mm/vmscan: never demote for memcg reclaim Huang Ying
2021-06-18 6:15 ` [PATCH -V8 10/10] mm/migrate: add sysfs interface to enable reclaim migration Huang Ying
2021-06-22 9:00 ` [PATCH -V8 00/10] Migrate Pages in lieu of discard Oscar Salvador
2021-06-23 1:12 ` Huang, Ying
2021-06-23 1:12 ` Huang, Ying
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