From mboxrd@z Thu Jan 1 00:00:00 1970 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 EF509C19F2D for ; Tue, 9 Aug 2022 05:34:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 75EF78E0002; Tue, 9 Aug 2022 01:34:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 70F086B0072; Tue, 9 Aug 2022 01:34:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5B09B8E0002; Tue, 9 Aug 2022 01:34:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 4B8196B0071 for ; Tue, 9 Aug 2022 01:34:31 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 2C9F01C637A for ; Tue, 9 Aug 2022 05:34:31 +0000 (UTC) X-FDA: 79778939142.03.67FE04A Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by imf10.hostedemail.com (Postfix) with ESMTP id C6AD3C0054 for ; Tue, 9 Aug 2022 05:34:30 +0000 (UTC) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 2795Nw0h007796; Tue, 9 Aug 2022 05:34:21 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=/7Op0SDmAucXIzTtF4ws6gTT63IRBMOXdXdJVJa8Q7s=; b=ZqZ+v0xuro9UDZZ6pm4iPP5i2wpzydkmF/1yHX6CcLRKY6ATTGuPais2hWifoGvUGp32 R7spqVtFruRAEGBj93fCPzn7/cLyY8rIwj+QOTbaMzAHM9xTI0NJLXd8OZ4wW8ZW5i8H z21N820EHLIB/Uh8cRy0EAe46B7it+C+nM/V8kMUZ9WxP6whA99EirShvEfSpXQjxrI4 Gq3TIIJNCn9WyW+xi680skAz2EwgBQiT1NEZX79c4Oe5ZskNkvmawcchNxIYBxEG+1W0 C5557Kbw3YOG+ChydAutyLdGl1o03FraX7A+fMvWKzij4uO6lh6EWM7iXXVv+y3oFqHG qg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3huhd107a4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 Aug 2022 05:34:20 +0000 Received: from m0098421.ppops.net (m0098421.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 2795OZMb010627; Tue, 9 Aug 2022 05:34:20 GMT Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3huhd1079f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 Aug 2022 05:34:20 +0000 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 2795LDse014372; Tue, 9 Aug 2022 05:34:18 GMT Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by ppma06ams.nl.ibm.com with ESMTP id 3hu4rp8mrq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 Aug 2022 05:34:18 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 2795YGPA33096052 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 9 Aug 2022 05:34:16 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 22FF5AE04D; Tue, 9 Aug 2022 05:34:16 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C6655AE045; Tue, 9 Aug 2022 05:34:12 +0000 (GMT) Received: from [9.109.205.170] (unknown [9.109.205.170]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 9 Aug 2022 05:34:12 +0000 (GMT) Message-ID: Date: Tue, 9 Aug 2022 11:04:11 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.12.0 Subject: Re: [PATCH v13 1/9] mm/demotion: Add support for explicit memory tiers Content-Language: en-US To: "Huang, Ying" Cc: linux-mm@kvack.org, akpm@linux-foundation.org, Wei Xu , Yang Shi , Davidlohr Bueso , Tim C Chen , Michal Hocko , Linux Kernel Mailing List , Hesham Almatary , Dave Hansen , Jonathan Cameron , Alistair Popple , Dan Williams , Johannes Weiner , jvgediya.oss@gmail.com References: <20220808062601.836025-1-aneesh.kumar@linux.ibm.com> <20220808062601.836025-2-aneesh.kumar@linux.ibm.com> <87sfm6gotr.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Aneesh Kumar K V In-Reply-To: <87sfm6gotr.fsf@yhuang6-desk2.ccr.corp.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: P1QL-dScocUkPuhw1LNaLEoR2Hm60lXs X-Proofpoint-ORIG-GUID: ykTwLxnC0a-SB0LP137Ko4x1ZyKm-MCL X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-08_14,2022-08-09_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 bulkscore=0 clxscore=1015 malwarescore=0 priorityscore=1501 lowpriorityscore=0 phishscore=0 spamscore=0 mlxlogscore=999 suspectscore=0 impostorscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2208090023 ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=ZqZ+v0xu; spf=pass (imf10.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.158.5 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660023270; a=rsa-sha256; cv=none; b=mTO9VQ9SQtf1H/8axu6W0lEUujieqXCWMz9x26nU8DgHajznwwX1xXVTMEMUJNco9+nFGC TNq1/TK9Weg30RSHCrenwMRudhvIIbTtPaCELUA/44i9Y+5tKnbSdJnIOMD1VWUfe88VY0 Kg0jpwrMtiX5MK7ktsTfi+UnadxQzjs= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660023270; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/7Op0SDmAucXIzTtF4ws6gTT63IRBMOXdXdJVJa8Q7s=; b=V+2D6zhPKC6vECW+UDAROGfvngvVJZyknkXW8CndT7Pwou5se2H+WMHFn+NU/ujpL/3KiH lj6868gF8c2AqwvtvwdhVgGoeR9+fMfF9yv9OQQd0d7lx0uL+o8qdZwy/2uVs6+nxyKynY Ock2ZKja9fjh9H62S9v0hRTDikbxvnc= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C6AD3C0054 X-Rspam-User: Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=ZqZ+v0xu; spf=pass (imf10.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.158.5 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com X-Stat-Signature: uoy91b3tuu851jsy1gt5y9gi15w3atc5 X-HE-Tag: 1660023270-133289 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: On 8/9/22 7:28 AM, Huang, Ying wrote: > "Aneesh Kumar K.V" writes: > >> 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 highest tier, and builds >> the tier hierarchy by establishing the per-node demotion targets based on the >> distances between nodes. >> >> This current memory tier kernel implementation 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-backed memory-only node on a virtual machine) that >> 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 or GPU devices, the memory-only NUMA nodes mapping these devices >> should be in the top tier, and DRAM nodes with CPUs are better to be placed into >> the next lower tier. >> >> With current kernel higher tier node can only be demoted to nodes with shortest >> distance on the next lower tier as defined by the demotion path, not any other >> node from any lower tier. This strict, 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), 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. >> >> This patch series address the above by defining memory tiers explicitly. >> >> Linux kernel presents memory devices as NUMA nodes and each memory device is of >> a specific type. The memory type of a device is represented by its abstract >> distance. A memory tier corresponds to a range of abstract distance. This allows >> for classifying memory devices with a specific performance range into a memory >> tier. >> >> This patch configures the range/chunk size to be 128. The default DRAM abstract >> distance is 512. We can have 4 memory tiers below the default DRAM with abstract >> distance range 0 - 127, 127 - 255, 256- 383, 384 - 511. Faster memory devices >> can be placed in these faster(higher) memory tiers. Slower memory devices like >> persistent memory will have abstract distance higher than the default DRAM >> level. >> >> Signed-off-by: Aneesh Kumar K.V >> --- >> include/linux/memory-tiers.h | 15 +++++ >> mm/Makefile | 1 + >> mm/memory-tiers.c | 107 +++++++++++++++++++++++++++++++++++ >> 3 files changed, 123 insertions(+) >> create mode 100644 include/linux/memory-tiers.h >> create mode 100644 mm/memory-tiers.c >> >> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h >> new file mode 100644 >> index 000000000000..bc7c1b799bef >> --- /dev/null >> +++ b/include/linux/memory-tiers.h >> @@ -0,0 +1,15 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +#ifndef _LINUX_MEMORY_TIERS_H >> +#define _LINUX_MEMORY_TIERS_H >> + >> +/* >> + * Each tier cover a abstrace distance chunk size of 128 >> + */ >> +#define MEMTIER_CHUNK_BITS 7 >> +#define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS) >> +/* >> + * Smaller abstract distance value imply faster(higher) memory tiers. >> + */ >> +#define MEMTIER_ADISTANCE_DRAM (4 * MEMTIER_CHUNK_SIZE) >> + >> +#endif /* _LINUX_MEMORY_TIERS_H */ >> diff --git a/mm/Makefile b/mm/Makefile >> index 6f9ffa968a1a..d30acebc2164 100644 >> --- a/mm/Makefile >> +++ b/mm/Makefile >> @@ -92,6 +92,7 @@ obj-$(CONFIG_KFENCE) += kfence/ >> obj-$(CONFIG_FAILSLAB) += failslab.o >> obj-$(CONFIG_MEMTEST) += memtest.o >> obj-$(CONFIG_MIGRATION) += migrate.o >> +obj-$(CONFIG_NUMA) += memory-tiers.o >> obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o >> obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o >> obj-$(CONFIG_PAGE_COUNTER) += page_counter.o >> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c >> new file mode 100644 >> index 000000000000..78b311d9bde9 >> --- /dev/null >> +++ b/mm/memory-tiers.c >> @@ -0,0 +1,107 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +struct memory_tier { >> + /* hierarchy of memory tiers */ >> + struct list_head list; >> + /* list of all memory types part of this tier */ >> + struct list_head memory_types; >> + /* >> + * start value of abstract distance. memory tier maps >> + * an abstract distance range, >> + * adistance_start .. adistance_start + MEMTIER_CHUNK_SIZE >> + */ >> + int adistance_start; >> +}; >> + >> +struct memory_dev_type { >> + /* list of memory types that are part of same tier as this type */ >> + struct list_head tier_sibiling; >> + /* abstract distance for this specific memory type */ >> + int adistance; >> + /* Nodes of same abstract distance */ >> + nodemask_t nodes; >> + struct memory_tier *memtier; >> +}; >> + >> +static DEFINE_MUTEX(memory_tier_lock); >> +static LIST_HEAD(memory_tiers); >> +static struct memory_dev_type *node_memory_types[MAX_NUMNODES]; >> +/* >> + * For now let's have 4 memory tier below default DRAM tier. >> + */ >> +static struct memory_dev_type default_dram_type = { >> + .adistance = MEMTIER_ADISTANCE_DRAM, >> + .tier_sibiling = LIST_HEAD_INIT(default_dram_type.tier_sibiling), >> +}; >> + >> +static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memtype) >> +{ >> + bool found_slot = false; >> + struct memory_tier *memtier, *new_memtier; >> + int adistance = memtype->adistance; >> + unsigned int memtier_adistance_chunk_size = MEMTIER_CHUNK_SIZE; >> + >> + lockdep_assert_held_once(&memory_tier_lock); >> + >> + /* >> + * If the memtype is already part of a memory tier, >> + * just return that. >> + */ >> + if (memtype->memtier) >> + return memtype->memtier; >> + >> + adistance = round_down(adistance, memtier_adistance_chunk_size); >> + list_for_each_entry(memtier, &memory_tiers, list) { >> + if (adistance == memtier->adistance_start) { >> + memtype->memtier = memtier; >> + list_add(&memtype->tier_sibiling, &memtier->memory_types); >> + return memtier; >> + } else if (adistance < memtier->adistance_start) { >> + found_slot = true; >> + break; >> + } >> + } >> + >> + new_memtier = kmalloc(sizeof(struct memory_tier), GFP_KERNEL); >> + if (!new_memtier) >> + return ERR_PTR(-ENOMEM); >> + >> + new_memtier->adistance_start = adistance; >> + INIT_LIST_HEAD(&new_memtier->list); >> + INIT_LIST_HEAD(&new_memtier->memory_types); >> + if (found_slot) >> + list_add_tail(&new_memtier->list, &memtier->list); >> + else >> + list_add_tail(&new_memtier->list, &memory_tiers); >> + memtype->memtier = new_memtier; >> + list_add(&memtype->tier_sibiling, &new_memtier->memory_types); >> + return new_memtier; >> +} >> + >> +static int __init memory_tier_init(void) >> +{ >> + int node; >> + struct memory_tier *memtier; >> + >> + mutex_lock(&memory_tier_lock); >> + /* CPU only nodes are not part of memory tiers. */ >> + default_dram_type.nodes = node_states[N_MEMORY]; >> + >> + memtier = find_create_memory_tier(&default_dram_type); >> + if (IS_ERR(memtier)) >> + panic("%s() failed to register memory tier: %ld\n", >> + __func__, PTR_ERR(memtier)); >> + >> + for_each_node_state(node, N_MEMORY) >> + node_memory_types[node] = &default_dram_type; > > Although not absolutely necessary, it seems better to set > node_memory_types[] before adding nodes to the memory type and adding > the memory type to the memory tier. > > updated. -aneesh