From patchwork Fri Jun 10 13:49:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 12877618 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D55D5C43334 for ; Fri, 10 Jun 2022 13:52:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 54C758D00A1; Fri, 10 Jun 2022 09:52:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 43A1E8D009C; Fri, 10 Jun 2022 09:52:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23D998D00A1; Fri, 10 Jun 2022 09:52:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 0E65B8D009C for ; Fri, 10 Jun 2022 09:52:12 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id DD0221202E4 for ; Fri, 10 Jun 2022 13:52:11 +0000 (UTC) X-FDA: 79562465262.22.4C5CF66 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf18.hostedemail.com (Postfix) with ESMTP id 3D8E01C006F for ; Fri, 10 Jun 2022 13:52:11 +0000 (UTC) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25ADgdSf000460; Fri, 10 Jun 2022 13:50:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=ESZ79LDKw4Og1Sb2xDSPQAbZQmnUmVjDYMVu/+zaIOo=; b=hhXt+aF/W+fqWoB1WPNGdU4lEfn03kppuKOsPEwy8IkL6CxyhlOxDQJl7ZSFsryOEPTv SgSD2t5d5stIZUuz56aH8g5snSyL0Es73iL8N/LV/KuhXhZc3ES7Xacvc2p/PEy2BeAn pmcdmRaPqExEWyCFT0YTY5ub8GwvTMPnnnlSa7JEt4+0XAYXSZVf2fgOIv5234c7LdCD XHTIgr1vWFqrkWoBOsTv7zu9D5GhIHHj2ZejdrqsKuCQY7ls58RLESV/IAxAkR3vNn7c d2YrJ7mFgr5GaNAq+gu/fvEbDT5B8lHs/1lNhKje5Y1QW+ENzzrYBcvxZr18gnqduTsI 4Q== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3gm72vr4rn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 10 Jun 2022 13:50:45 +0000 Received: from m0098393.ppops.net (m0098393.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 25ADiXN8004585; Fri, 10 Jun 2022 13:50:45 GMT Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3gm72vr4r7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 10 Jun 2022 13:50:45 +0000 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 25ADZSsR014169; Fri, 10 Jun 2022 13:50:44 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma02dal.us.ibm.com with ESMTP id 3gfy1bb42c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 10 Jun 2022 13:50:44 +0000 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 25ADogRi35652054 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 10 Jun 2022 13:50:42 GMT Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 86BEA6A047; Fri, 10 Jun 2022 13:50:42 +0000 (GMT) Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A1F076A04F; Fri, 10 Jun 2022 13:50:34 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.43.90.151]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP; Fri, 10 Jun 2022 13:50:34 +0000 (GMT) From: "Aneesh Kumar K.V" To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: Wei Xu , Huang Ying , Greg Thelen , Yang Shi , Davidlohr Bueso , Tim C Chen , Brice Goglin , Michal Hocko , Linux Kernel Mailing List , Hesham Almatary , Dave Hansen , Jonathan Cameron , Alistair Popple , Dan Williams , Feng Tang , Jagdish Gediya , Baolin Wang , David Rientjes , "Aneesh Kumar K.V" Subject: [PATCH v6 00/13] mm/demotion: Memory tiers and demotion Date: Fri, 10 Jun 2022 19:19:53 +0530 Message-Id: <20220610135006.182507-1-aneesh.kumar@linux.ibm.com> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: AkJwcwOFp1YlfnV2dMT_lMlBXGVtZAMv X-Proofpoint-GUID: 7cNiVZgrt86ggQFUTrjncSIHGw3TcYsO X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-10_06,2022-06-09_02,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 spamscore=0 malwarescore=0 bulkscore=0 impostorscore=0 clxscore=1015 priorityscore=1501 mlxlogscore=999 mlxscore=0 adultscore=0 lowpriorityscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2204290000 definitions=main-2206100052 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1654869131; a=rsa-sha256; cv=none; b=7rarFJCIXpAjvOVwrAK7pqzioULrfD/s7uR2O3DiYJiVQyoVxV9Qk4SuilIhYOl9oHOTc+ f8HxKsfV1NgQNkU47MYXuNN9WKZoQ5bzaz3mIBxOE+FMJehve+PCcdG5de2EWp1UvbgjuY 1EleW/uKdECe0AWGEZbNnkoCM88DN3E= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b="hhXt+aF/"; dmarc=pass (policy=none) header.from=ibm.com; spf=pass (imf18.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1654869131; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=ESZ79LDKw4Og1Sb2xDSPQAbZQmnUmVjDYMVu/+zaIOo=; b=PrHT+KgSzsjRNUFIRGQnNQrOqTqBW2vhiU8JnRhSa23t0zYRnImahdGQac9HcSWNy804fT 0i0r721l/RSJb4MMS4MxQaCuMq0y6yvcFfp9qH7idYeY4QnWx8iHvPuxPACp38/b683a80 nKI0RJdbUvfbZ9t7z9fJyevLpJ+vQa4= X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 3D8E01C006F Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b="hhXt+aF/"; dmarc=pass (policy=none) header.from=ibm.com; spf=pass (imf18.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com X-Stat-Signature: u64t645mnawo9wue4brau7wp5g6chgsi X-HE-Tag: 1654869131-686201 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The current kernel has the basic memory tiering support: Inactive pages on a higher tier NUMA node can be migrated (demoted) to a lower tier NUMA node to make room for new allocations on the higher tier NUMA node. Frequently accessed pages on a lower tier NUMA node can be migrated (promoted) to a higher tier NUMA node to improve the performance. In the current kernel, memory tiers are defined implicitly via a demotion path relationship between NUMA nodes, which is created during the kernel initialization and updated when a NUMA node is hot-added or hot-removed. The current implementation puts all nodes with CPU into the top tier, and builds the tier hierarchy tier-by-tier by establishing the per-node demotion targets based on the distances between nodes. This current memory tier kernel interface needs to be improved for several important use cases: * The current tier initialization code always initializes each memory-only NUMA node into a lower tier. But a memory-only NUMA node may have a high performance memory device (e.g. a DRAM device attached via CXL.mem or a DRAM-backed memory-only node on a virtual machine) and should be put into a higher tier. * The current tier hierarchy always puts CPU nodes into the top tier. But on a system with HBM (e.g. GPU memory) devices, these memory-only HBM NUMA nodes should be in the top tier, and DRAM nodes with CPUs are better to be placed into the next lower tier. * Also because the current tier hierarchy always puts CPU nodes into the top tier, when a CPU is hot-added (or hot-removed) and triggers a memory node from CPU-less into a CPU node (or vice versa), the memory tier hierarchy gets changed, even though no memory node is added or removed. This can make the tier hierarchy unstable and make it difficult to support tier-based memory accounting. * A higher tier node can only be demoted to selected nodes on the next lower tier as defined by the demotion path, not any other node from any lower tier. This strict, hard-coded demotion order does not work in all use cases (e.g. some use cases may want to allow cross-socket demotion to another node in the same demotion tier as a fallback when the preferred demotion node is out of space), and has resulted in the feature request for an interface to override the system-wide, per-node demotion order from the userspace. This demotion order is also inconsistent with the page allocation fallback order when all the nodes in a higher tier are out of space: The page allocation can fall back to any node from any lower tier, whereas the demotion order doesn't allow that. * There are no interfaces for the userspace to learn about the memory tier hierarchy in order to optimize its memory allocations. This patch series make the creation of memory tiers explicit under the control of userspace or device driver. Memory Tier Initialization ========================== By default, all memory nodes are assigned to the default tier (1). The default tier device has a rank value (200). A device driver can move up or down its memory nodes from the default tier. For example, PMEM can move down its memory nodes below the default tier, whereas GPU can move up its memory nodes above the default tier. The kernel initialization code makes the decision on which exact tier a memory node should be assigned to based on the requests from the device drivers as well as the memory device hardware information provided by the firmware. Hot-adding/removing CPUs doesn't affect memory tier hierarchy. Memory Allocation for Demotion ============================== This patch series keep the demotion target page allocation logic same. The demotion page allocation pick the closest NUMA node in the next lower tier to the current NUMA node allocating pages from. This will be later improved to use the same page allocation strategy using fallback list. Sysfs Interface: ======================= Listing current list of memory tiers and rank details: :/sys/devices/system/memtier$ ls default_tier max_tier memtier1 power uevent :/sys/devices/system/memtier$ cat default_tier memtier1 :/sys/devices/system/memtier$ cat max_tier 3 :/sys/devices/system/memtier$ Per node memory tier details: For a cpu only NUMA node: :/sys/devices/system/node# cat node0/memtier :/sys/devices/system/node# echo 1 > node0/memtier :/sys/devices/system/node# cat node0/memtier :/sys/devices/system/node# For a NUMA node with memory: :/sys/devices/system/node# cat node1/memtier 1 :/sys/devices/system/node# ls ../memtier/ default_tier max_tier memtier1 power uevent :/sys/devices/system/node# echo 2 > node1/memtier :/sys/devices/system/node# :/sys/devices/system/node# ls ../memtier/ default_tier max_tier memtier1 memtier2 power uevent :/sys/devices/system/node# cat node1/memtier 2 :/sys/devices/system/node# :/sys/devices/system/node# cat ../memtier/memtier2/rank 100 :/sys/devices/system/node# :/sys/devices/system/node# cat ../memtier/memtier1/rank 200 :/sys/devices/system/node# Removing a NUMA node from demotion: :/sys/devices/system/node# cat node1/memtier 2 :/sys/devices/system/node# echo none > node1/memtier :/sys/devices/system/node# :/sys/devices/system/node# cat node1/memtier :/sys/devices/system/node# :/sys/devices/system/node# ls ../memtier/ default_tier max_tier memtier1 power uevent :/sys/devices/system/node# The above also resulted in removal of memtier2 which was created in the earlier step. Changes from v5: * Remove patch supporting N_MEMORY node removal from memory tiers. memory tiers are going to be used for features other than demotion. Hence keep all N_MEMORY nodes in memory tiers irrespective of whether they want to participate in promotion or demotion. * Add NODE_DATA->memtier * Rearrage patches to add sysfs files later. * Add support to create memory tiers from userspace. * Address other review feedback. Changes from v4: * Address review feedback. * Reverse the meaning of "rank": higher rank value means higher tier. * Add "/sys/devices/system/memtier/default_tier". * Add node_is_toptier v4: Add support for explicit memory tiers and ranks. v3: - Modify patch 1 subject to make it more specific - Remove /sys/kernel/mm/numa/demotion_targets interface, use /sys/devices/system/node/demotion_targets instead and make it writable to override node_states[N_DEMOTION_TARGETS]. - Add support to view per node demotion targets via sysfs v2: In v1, only 1st patch of this patch series was sent, which was implemented to avoid some of the limitations on the demotion target sharing, however for certain numa topology, the demotion targets found by that patch was not most optimal, so 1st patch in this series is modified according to suggestions from Huang and Baolin. Different examples of demotion list comparasion between existing implementation and changed implementation can be found in the commit message of 1st patch. Aneesh Kumar K.V (11): mm/demotion: Add support for explicit memory tiers mm/demotion: Move memory demotion related code mm/demotion: Return error on write to numa_demotion sysfs mm/demotion/dax/kmem: Set node's memory tier to MEMORY_TIER_PMEM mm/demotion: Build demotion targets based on explicit memory tiers mm/demotion: Expose memory tier details via sysfs mm/demotion: Add per node memory tier attribute to sysfs mm/demotion: Add support for memory tier creation from userspace mm/demotion: Add pg_data_t member to track node memory tier details mm/demotion: Update node_is_toptier to work with memory tiers mm/demotion: Add sysfs ABI documentation Jagdish Gediya (2): mm/demotion: Demote pages according to allocation fallback order mm/demotion: Add documentation for memory tiering .../ABI/testing/sysfs-kernel-mm-memory-tiers | 87 ++ Documentation/admin-guide/mm/index.rst | 1 + .../admin-guide/mm/memory-tiering.rst | 181 ++++ drivers/base/node.c | 39 + drivers/dax/kmem.c | 4 + include/linux/memory-tiers.h | 63 ++ include/linux/migrate.h | 15 - include/linux/mmzone.h | 3 + include/linux/node.h | 5 - mm/Kconfig | 3 + mm/Makefile | 1 + mm/huge_memory.c | 1 + mm/memory-tiers.c | 888 ++++++++++++++++++ mm/migrate.c | 453 +-------- mm/mprotect.c | 1 + mm/vmscan.c | 57 +- mm/vmstat.c | 4 - 17 files changed, 1316 insertions(+), 490 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers create mode 100644 Documentation/admin-guide/mm/memory-tiering.rst create mode 100644 include/linux/memory-tiers.h create mode 100644 mm/memory-tiers.c