From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: Wei Xu <weixugc@google.com>, Huang Ying <ying.huang@intel.com>,
Greg Thelen <gthelen@google.com>, Yang Shi <shy828301@gmail.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Tim C Chen <tim.c.chen@intel.com>,
Brice Goglin <brice.goglin@gmail.com>,
Michal Hocko <mhocko@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Hesham Almatary <hesham.almatary@huawei.com>,
Dave Hansen <dave.hansen@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Alistair Popple <apopple@nvidia.com>,
Dan Williams <dan.j.williams@intel.com>,
Feng Tang <feng.tang@intel.com>,
Jagdish Gediya <jvgediya@linux.ibm.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
David Rientjes <rientjes@google.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: [PATCH v6 13/13] mm/demotion: Add sysfs ABI documentation
Date: Fri, 10 Jun 2022 19:22:29 +0530 [thread overview]
Message-ID: <20220610135229.182859-14-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20220610135229.182859-1-aneesh.kumar@linux.ibm.com>
Add sysfs ABI documentation.
Signed-off-by: Wei Xu <weixugc@google.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
.../ABI/testing/sysfs-kernel-mm-memory-tiers | 87 +++++++++++++++++++
1 file changed, 87 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers
diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers b/Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers
new file mode 100644
index 000000000000..b41d2977b0a5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers
@@ -0,0 +1,87 @@
+What: /sys/devices/system/memtier/
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Interface for tiered memory
+
+ This is the directory containing the information about memory tiers.
+
+ Each memory tier has its own subdirectory.
+
+ The order of memory tiers is determined by their rank values, not by
+ their memtier device names. A higher rank value means a higher tier.
+
+What: /sys/devices/system/memtier/default_tier
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Default memory tier
+
+ The default memory tier to which memory would get added via hotplug
+ if the NUMA node is not part of any memory tier
+
+What: /sys/devices/system/memtier/max_tier
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Maximum number of memory tiers supported
+
+ The max memory tier device ID we can create. Users can create memory
+ tiers in range [0 - max_tier)
+
+What: /sys/devices/system/memtier/create_tier_from_rank
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Interface to create memory tiers from userspace
+
+ Writing to this file with a rank value results in creation of
+ a new memory tier with the specified rank value. This is used
+ by userspace to create new memory tiers.
+
+What: /sys/devices/system/memtier/memtierN/
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Directory with details of a specific memory tier
+
+ This is the directory containing the information about a particular
+ memory tier, memtierN, where N is the memtier device ID (e.g. 0, 1).
+
+ The memtier device ID number itself is just an identifier and has no
+ special meaning, i.e. memtier device ID numbers do not determine the
+ order of memory tiers.
+
+What: /sys/devices/system/memtier/memtierN/rank
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Memory tier rank value
+
+
+ When read, list the "rank" value associated with memtierN.
+
+ "Rank" is an opaque value. Its absolute value doesn't have any
+ special meaning. But the rank values of different memtiers can be
+ compared with each other to determine the memory tier order.
+
+ For example, if we have 3 memtiers: memtier0, memtier1, memiter2, and
+ their rank values are 100, 10, 50, then the memory tier order is:
+ memtier0 -> memtier2 -> memtier1, where memtier0 is the highest tier
+ and memtier1 is the lowest tier.
+
+ The rank value of each memtier should be unique.
+
+What: /sys/devices/system/memtier/memtierN/nodelist
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Memory tier nodelist
+
+
+ When read, list the memory nodes in the specified tier.
+
+What: /sys/devices/system/node/nodeN/memtier
+Date: June 2022
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Memory tier details for node N
+
+ When read, list the device ID of the memory tier that the node belongs
+ to. Its value is empty for a CPU-only NUMA node.
+
+ When written, the kernel moves the node into the specified memory
+ tier if the move is allowed. The tier assignments of all other
+ nodes are not affected.
--
2.36.1
prev parent reply other threads:[~2022-06-10 13:55 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-10 13:52 [PATCH v6 00/13] mm/demotion: Memory tiers and demotion Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 01/13] mm/demotion: Add support for explicit memory tiers Aneesh Kumar K.V
2022-06-13 3:22 ` Ying Huang
2022-06-13 3:31 ` Aneesh Kumar K V
2022-06-13 5:30 ` Ying Huang
2022-06-13 13:16 ` Johannes Weiner
2022-06-13 13:28 ` Aneesh Kumar K V
2022-06-14 8:20 ` Aneesh Kumar K.V
2022-06-14 15:13 ` Davidlohr Bueso
2022-06-10 13:52 ` [PATCH v6 02/13] mm/demotion: Move memory demotion related code Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 03/13] mm/demotion: Return error on write to numa_demotion sysfs Aneesh Kumar K.V
2022-06-13 3:26 ` Ying Huang
2022-06-13 3:35 ` Aneesh Kumar K V
2022-06-13 5:33 ` Ying Huang
2022-06-13 5:48 ` Aneesh Kumar K V
2022-06-14 8:40 ` Ying Huang
2022-06-10 13:52 ` [PATCH v6 04/13] mm/demotion/dax/kmem: Set node's memory tier to MEMORY_TIER_PMEM Aneesh Kumar K.V
2022-06-13 6:59 ` Ying Huang
2022-06-13 7:05 ` Aneesh Kumar K V
2022-06-10 13:52 ` [PATCH v6 05/13] mm/demotion: Build demotion targets based on explicit memory tiers Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 06/13] mm/demotion: Expose memory tier details via sysfs Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 07/13] mm/demotion: Add per node memory tier attribute to sysfs Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 08/13] mm/demotion: Add support for memory tier creation from userspace Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 09/13] mm/demotion: Add pg_data_t member to track node memory tier details Aneesh Kumar K.V
2022-06-13 7:07 ` Ying Huang
2022-06-10 13:52 ` [PATCH v6 10/13] mm/demotion: Demote pages according to allocation fallback order Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 11/13] mm/demotion: Update node_is_toptier to work with memory tiers Aneesh Kumar K.V
2022-06-10 13:52 ` [PATCH v6 12/13] mm/demotion: Add documentation for memory tiering Aneesh Kumar K.V
2022-06-10 13:52 ` Aneesh Kumar K.V [this message]
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