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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DBA4C6FA82 for ; Wed, 14 Sep 2022 22:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229487AbiINW2t (ORCPT ); Wed, 14 Sep 2022 18:28:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229716AbiINW2i (ORCPT ); Wed, 14 Sep 2022 18:28:38 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 206C1326CD for ; Wed, 14 Sep 2022 15:28:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A47A9B81CEC for ; Wed, 14 Sep 2022 22:28:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AAF4C433C1; Wed, 14 Sep 2022 22:28:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1663194514; bh=ap19U3UYqFgQWuA52gmmTzGpqKv7a7LgEw52qHDIRXE=; h=Date:To:From:Subject:From; b=A8QjhT64G5fVw6wvdL2iWl+uJadHPDneLDgvCrlg/7ydw3402CLgZ5LzktSNu0qru /kIKlJGNd2Nm15TPdzIsBRa+Q+zTVdOj+TdR7/AGwFL+riaF+9fXLhpwtTPC/A7vjP 4BAFrquD5/ZK43IB/vrpLroLNLmvr/ST+bUrEv/o= Date: Wed, 14 Sep 2022 15:28:33 -0700 To: mm-commits@vger.kernel.org, rafael@kernel.org, osalvador@suse.de, mike.kravetz@oracle.com, gregkh@linuxfoundation.org, david@redhat.com, andi@firstfloor.org, songmuchun@bytedance.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-eliminate-memory-less-nodes-handling.patch added to mm-unstable branch Message-Id: <20220914222834.5AAF4C433C1@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: hugetlb: eliminate memory-less nodes handling has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-eliminate-memory-less-nodes-handling.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-eliminate-memory-less-nodes-handling.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Muchun Song Subject: mm: hugetlb: eliminate memory-less nodes handling Date: Wed, 14 Sep 2022 15:26:03 +0800 The memory-notify-based approach aims to handle meory-less nodes, however, it just adds the complexity of code as pointed by David in thread [1]. The handling of memory-less nodes is introduced by commit 4faf8d950ec4 ("hugetlb: handle memory hot-plug events"). >From its commit message, we cannot find any necessity of handling this case. So, we can simply register/unregister sysfs entries in register_node/unregister_node to simlify the code. BTW, hotplug callback added because in hugetlb_register_all_nodes() we register sysfs nodes only for N_MEMORY nodes, seeing commit 9b5e5d0fdc91, which said it was a preparation for handling memory-less nodes via memory hotplug. Since we want to remove memory hotplug, so make sure we only register per-node sysfs for online (N_ONLINE) nodes in hugetlb_register_all_nodes(). https://lore.kernel.org/linux-mm/60933ffc-b850-976c-78a0-0ee6e0ea9ef0@redhat.com/ [1] Link: https://lkml.kernel.org/r/20220914072603.60293-3-songmuchun@bytedance.com Suggested-by: David Hildenbrand Signed-off-by: Muchun Song Acked-by: David Hildenbrand Cc: Andi Kleen Cc: Greg Kroah-Hartman Cc: Mike Kravetz Cc: Oscar Salvador Cc: Rafael J. Wysocki Signed-off-by: Andrew Morton --- drivers/base/node.c | 8 +++- include/linux/hugetlb.h | 14 +++++++ mm/hugetlb.c | 70 +++++++++++++++----------------------- 3 files changed, 49 insertions(+), 43 deletions(-) --- a/drivers/base/node.c~mm-hugetlb-eliminate-memory-less-nodes-handling +++ a/drivers/base/node.c @@ -20,6 +20,7 @@ #include #include #include +#include static struct bus_type node_subsys = { .name = "node", @@ -608,10 +609,12 @@ static int register_node(struct node *no node->dev.groups = node_dev_groups; error = device_register(&node->dev); - if (error) + if (error) { put_device(&node->dev); - else + } else { + hugetlb_register_node(node); compaction_register_node(node); + } return error; } @@ -625,6 +628,7 @@ static int register_node(struct node *no */ void unregister_node(struct node *node) { + hugetlb_unregister_node(node); compaction_unregister_node(node); node_remove_accesses(node); node_remove_caches(node); --- a/include/linux/hugetlb.h~mm-hugetlb-eliminate-memory-less-nodes-handling +++ a/include/linux/hugetlb.h @@ -16,6 +16,7 @@ struct ctl_table; struct user_struct; struct mmu_gather; +struct node; #ifndef is_hugepd typedef struct { unsigned long pd; } hugepd_t; @@ -935,6 +936,11 @@ static inline void huge_ptep_modify_prot } #endif +#ifdef CONFIG_NUMA +void hugetlb_register_node(struct node *node); +void hugetlb_unregister_node(struct node *node); +#endif + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; @@ -1109,6 +1115,14 @@ static inline void set_huge_pte_at(struc pte_t *ptep, pte_t pte) { } + +static inline void hugetlb_register_node(struct node *node) +{ +} + +static inline void hugetlb_unregister_node(struct node *node) +{ +} #endif /* CONFIG_HUGETLB_PAGE */ static inline spinlock_t *huge_pte_lock(struct hstate *h, --- a/mm/hugetlb.c~mm-hugetlb-eliminate-memory-less-nodes-handling +++ a/mm/hugetlb.c @@ -3871,24 +3871,8 @@ static int hugetlb_sysfs_add_hstate(stru return 0; } -static void __init hugetlb_sysfs_init(void) -{ - struct hstate *h; - int err; - - hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); - if (!hugepages_kobj) - return; - - for_each_hstate(h) { - err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, - hstate_kobjs, &hstate_attr_group); - if (err) - pr_err("HugeTLB: Unable to add hstate %s", h->name); - } -} - #ifdef CONFIG_NUMA +static bool hugetlb_sysfs_initialized __ro_after_init; /* * node_hstate/s - associate per node hstate attributes, via their kobjects, @@ -3944,7 +3928,7 @@ static struct hstate *kobj_to_node_hstat * Unregister hstate attributes from a single node device. * No-op if no hstate attributes attached. */ -static void hugetlb_unregister_node(struct node *node) +void hugetlb_unregister_node(struct node *node) { struct hstate *h; struct node_hstate *nhs = &node_hstates[node->dev.id]; @@ -3974,12 +3958,15 @@ static void hugetlb_unregister_node(stru * Register hstate attributes for a single node device. * No-op if attributes already registered. */ -static void hugetlb_register_node(struct node *node) +void hugetlb_register_node(struct node *node) { struct hstate *h; struct node_hstate *nhs = &node_hstates[node->dev.id]; int err; + if (!hugetlb_sysfs_initialized) + return; + if (nhs->hugepages_kobj) return; /* already allocated */ @@ -4001,23 +3988,6 @@ static void hugetlb_register_node(struct } } -static int __meminit hugetlb_memory_callback(struct notifier_block *self, - unsigned long action, void *arg) -{ - struct memory_notify *mnb = arg; - int nid = mnb->status_change_nid; - - if (nid == NUMA_NO_NODE) - return NOTIFY_DONE; - - if (action == MEM_GOING_ONLINE) - hugetlb_register_node(node_devices[nid]); - else if (action == MEM_CANCEL_ONLINE || action == MEM_OFFLINE) - hugetlb_unregister_node(node_devices[nid]); - - return NOTIFY_OK; -} - /* * hugetlb init time: register hstate attributes for all registered node * devices of nodes that have memory. All on-line nodes should have @@ -4027,11 +3997,8 @@ static void __init hugetlb_register_all_ { int nid; - get_online_mems(); - hotplug_memory_notifier(hugetlb_memory_callback, 0); - for_each_node_state(nid, N_MEMORY) + for_each_online_node(nid) hugetlb_register_node(node_devices[nid]); - put_online_mems(); } #else /* !CONFIG_NUMA */ @@ -4055,6 +4022,28 @@ static inline __init void hugetlb_cma_ch } #endif +static void __init hugetlb_sysfs_init(void) +{ + struct hstate *h; + int err; + + hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); + if (!hugepages_kobj) + return; + + for_each_hstate(h) { + err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, + hstate_kobjs, &hstate_attr_group); + if (err) + pr_err("HugeTLB: Unable to add hstate %s", h->name); + } + +#ifdef CONFIG_NUMA + hugetlb_sysfs_initialized = true; +#endif + hugetlb_register_all_nodes(); +} + static int __init hugetlb_init(void) { int i; @@ -4109,7 +4098,6 @@ static int __init hugetlb_init(void) report_hugepages(); hugetlb_sysfs_init(); - hugetlb_register_all_nodes(); hugetlb_cgroup_file_init(); #ifdef CONFIG_SMP _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-hugetlb-simplify-per-node-sysfs-creation-and-removal.patch mm-hugetlb-eliminate-memory-less-nodes-handling.patch