From patchwork Fri Oct 13 18:11:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 13421553 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 27053CDB47E for ; Fri, 13 Oct 2023 18:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231788AbjJMSNA (ORCPT ); Fri, 13 Oct 2023 14:13:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231522AbjJMSMt (ORCPT ); Fri, 13 Oct 2023 14:12:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8B06E3 for ; Fri, 13 Oct 2023 11:12:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697220724; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2+Udgd9t+oJaMjSuWvjsOR91eGe6O+i8JtL7jWCC2do=; b=N6QYRIL+H0w8DRFHMNVEnBSGdUfNGEApuEkedSU1lISGnx+rQ7xPX+lxfTcXXMD+HPmf02 DDRaCtqbJdr+7rv2aYf3C9FrVhZYgQAyKRHF7gue2x9SzNCufqA9/krEuyiYNN3N1tnbsm HoPHdiestNBKRnCDLGJldhTFZaX7mX8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-381-82XO3FSgP_yZC25qtn8fYA-1; Fri, 13 Oct 2023 14:11:50 -0400 X-MC-Unique: 82XO3FSgP_yZC25qtn8fYA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 092B4946DC5; Fri, 13 Oct 2023 18:11:50 +0000 (UTC) Received: from llong.com (unknown [10.22.17.138]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B5E320296DB; Fri, 13 Oct 2023 18:11:49 +0000 (UTC) From: Waiman Long To: Tejun Heo , Zefan Li , Johannes Weiner , Jonathan Corbet , Lai Jiangshan , Shuah Khan Cc: cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Waiman Long Subject: [PATCH-cgroup 3/4] cgroup/cpuset: Keep track of CPUs in isolated partitions Date: Fri, 13 Oct 2023 14:11:21 -0400 Message-Id: <20231013181122.3518610-4-longman@redhat.com> In-Reply-To: <20231013181122.3518610-1-longman@redhat.com> References: <20231013181122.3518610-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add a new internal isolated_cpus mask to keep track of the CPUs that are in isolated partitions. Expose that new cpumask as a new root-only control file ".__DEBUG__.cpuset.cpus.isolated" when cgroup_debug command line option is specified. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 190 +++++++++++++++++++++++++++-------------- 1 file changed, 127 insertions(+), 63 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 615daaf87f1f..19c8779798fd 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -204,6 +204,11 @@ struct cpuset { */ static cpumask_var_t subpartitions_cpus; +/* + * Exclusive CPUs in isolated partitions + */ +static cpumask_var_t isolated_cpus; + /* List of remote partition root children */ static struct list_head remote_children; @@ -1317,6 +1322,7 @@ static void compute_effective_cpumask(struct cpumask *new_cpus, */ enum partition_cmd { partcmd_enable, /* Enable partition root */ + partcmd_enablei, /* Enable isolated partition root */ partcmd_disable, /* Disable partition root */ partcmd_update, /* Update parent's effective_cpus */ partcmd_invalidate, /* Make partition invalid */ @@ -1418,6 +1424,74 @@ static void reset_partition_data(struct cpuset *cs) } } +/* + * partition_xcpus_newstate - Exclusive CPUs state change + * @old_prs: old partition_root_state + * @new_prs: new partition_root_state + * @xcpus: exclusive CPUs with state change + */ +static void partition_xcpus_newstate(int old_prs, int new_prs, struct cpumask *xcpus) +{ + WARN_ON_ONCE(old_prs == new_prs); + if (new_prs == PRS_ISOLATED) + cpumask_or(isolated_cpus, isolated_cpus, xcpus); + else + cpumask_andnot(isolated_cpus, isolated_cpus, xcpus); +} + +/* + * partition_xcpus_add - Add new exclusive CPUs to partition + * @new_prs: new partition_root_state + * @parent: parent cpuset + * @xcpus: exclusive CPUs to be added + * + * Remote partition if parent == NULL + */ +static void partition_xcpus_add(int new_prs, struct cpuset *parent, + struct cpumask *xcpus) +{ + WARN_ON_ONCE(new_prs < 0); + lockdep_assert_held(&callback_lock); + if (!parent) + parent = &top_cpuset; + + if (parent == &top_cpuset) + cpumask_or(subpartitions_cpus, subpartitions_cpus, xcpus); + + if (new_prs != parent->partition_root_state) + partition_xcpus_newstate(parent->partition_root_state, new_prs, + xcpus); + + cpumask_andnot(parent->effective_cpus, parent->effective_cpus, xcpus); +} + +/* + * partition_xcpus_del - Remove exclusive CPUs from partition + * @old_prs: old partition_root_state + * @parent: parent cpuset + * @xcpus: exclusive CPUs to be removed + * + * Remote partition if parent == NULL + */ +static void partition_xcpus_del(int old_prs, struct cpuset *parent, + struct cpumask *xcpus) +{ + WARN_ON_ONCE(old_prs < 0); + lockdep_assert_held(&callback_lock); + if (!parent) + parent = &top_cpuset; + + if (parent == &top_cpuset) + cpumask_andnot(subpartitions_cpus, subpartitions_cpus, xcpus); + + if (old_prs != parent->partition_root_state) + partition_xcpus_newstate(old_prs, parent->partition_root_state, + xcpus); + + cpumask_and(xcpus, xcpus, cpu_active_mask); + cpumask_or(parent->effective_cpus, parent->effective_cpus, xcpus); +} + /* * compute_effective_exclusive_cpumask - compute effective exclusive CPUs * @cs: cpuset @@ -1456,13 +1530,15 @@ static inline bool is_local_partition(struct cpuset *cs) /* * remote_partition_enable - Enable current cpuset as a remote partition root * @cs: the cpuset to update + * @new_prs: new partition_root_state * @tmp: temparary masks * Return: 1 if successful, 0 if error * * Enable the current cpuset to become a remote partition root taking CPUs * directly from the top cpuset. cpuset_mutex must be held by the caller. */ -static int remote_partition_enable(struct cpuset *cs, struct tmpmasks *tmp) +static int remote_partition_enable(struct cpuset *cs, int new_prs, + struct tmpmasks *tmp) { /* * The user must have sysadmin privilege. @@ -1485,18 +1561,14 @@ static int remote_partition_enable(struct cpuset *cs, struct tmpmasks *tmp) return 0; spin_lock_irq(&callback_lock); - cpumask_andnot(top_cpuset.effective_cpus, - top_cpuset.effective_cpus, tmp->new_cpus); - cpumask_or(subpartitions_cpus, - subpartitions_cpus, tmp->new_cpus); - + partition_xcpus_add(new_prs, NULL, tmp->new_cpus); + list_add(&cs->remote_sibling, &remote_children); if (cs->use_parent_ecpus) { struct cpuset *parent = parent_cs(cs); cs->use_parent_ecpus = false; parent->child_ecpus_count--; } - list_add(&cs->remote_sibling, &remote_children); spin_unlock_irq(&callback_lock); /* @@ -1524,13 +1596,8 @@ static void remote_partition_disable(struct cpuset *cs, struct tmpmasks *tmp) WARN_ON_ONCE(!cpumask_subset(tmp->new_cpus, subpartitions_cpus)); spin_lock_irq(&callback_lock); - cpumask_andnot(subpartitions_cpus, - subpartitions_cpus, tmp->new_cpus); - cpumask_and(tmp->new_cpus, - tmp->new_cpus, cpu_active_mask); - cpumask_or(top_cpuset.effective_cpus, - top_cpuset.effective_cpus, tmp->new_cpus); list_del_init(&cs->remote_sibling); + partition_xcpus_del(cs->partition_root_state, NULL, tmp->new_cpus); cs->partition_root_state = -cs->partition_root_state; if (!cs->prs_err) cs->prs_err = PERR_INVCPUS; @@ -1557,6 +1624,7 @@ static void remote_cpus_update(struct cpuset *cs, struct cpumask *newmask, struct tmpmasks *tmp) { bool adding, deleting; + int prs = cs->partition_root_state; if (WARN_ON_ONCE(!is_remote_partition(cs))) return; @@ -1580,20 +1648,10 @@ static void remote_cpus_update(struct cpuset *cs, struct cpumask *newmask, goto invalidate; spin_lock_irq(&callback_lock); - if (adding) { - cpumask_or(subpartitions_cpus, - subpartitions_cpus, tmp->addmask); - cpumask_andnot(top_cpuset.effective_cpus, - top_cpuset.effective_cpus, tmp->addmask); - } - if (deleting) { - cpumask_andnot(subpartitions_cpus, - subpartitions_cpus, tmp->delmask); - cpumask_and(tmp->delmask, - tmp->delmask, cpu_active_mask); - cpumask_or(top_cpuset.effective_cpus, - top_cpuset.effective_cpus, tmp->delmask); - } + if (adding) + partition_xcpus_add(prs, NULL, tmp->addmask); + if (deleting) + partition_xcpus_del(prs, NULL, tmp->delmask); spin_unlock_irq(&callback_lock); /* @@ -1676,11 +1734,11 @@ static bool prstate_housekeeping_conflict(int prstate, struct cpumask *new_cpus) * @tmp: Temporary addmask and delmask * Return: 0 or a partition root state error code * - * For partcmd_enable, the cpuset is being transformed from a non-partition - * root to a partition root. The effective_xcpus (cpus_allowed if effective_xcpus - * not set) mask of the given cpuset will be taken away from parent's - * effective_cpus. The function will return 0 if all the CPUs listed in - * effective_xcpus can be granted or an error code will be returned. + * For partcmd_enable*, the cpuset is being transformed from a non-partition + * root to a partition root. The effective_xcpus (cpus_allowed if + * effective_xcpus not set) mask of the given cpuset will be taken away from + * parent's effective_cpus. The function will return 0 if all the CPUs listed + * in effective_xcpus can be granted or an error code will be returned. * * For partcmd_disable, the cpuset is being transformed from a partition * root back to a non-partition root. Any CPUs in effective_xcpus will be @@ -1695,7 +1753,7 @@ static bool prstate_housekeeping_conflict(int prstate, struct cpumask *new_cpus) * * For partcmd_invalidate, the current partition will be made invalid. * - * The partcmd_enable and partcmd_disable commands are used by + * The partcmd_enable* and partcmd_disable commands are used by * update_prstate(). An error code may be returned and the caller will check * for error. * @@ -1760,7 +1818,7 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, nocpu = tasks_nocpu_error(parent, cs, xcpus); - if (cmd == partcmd_enable) { + if ((cmd == partcmd_enable) || (cmd == partcmd_enablei)) { /* * Enabling partition root is not allowed if its * effective_xcpus is empty or doesn't overlap with @@ -1783,6 +1841,7 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, cpumask_copy(tmp->delmask, xcpus); deleting = true; subparts_delta++; + new_prs = (cmd == partcmd_enable) ? PRS_ROOT : PRS_ISOLATED; } else if (cmd == partcmd_disable) { /* * May need to add cpus to parent's effective_cpus for @@ -1792,6 +1851,7 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, cpumask_and(tmp->addmask, xcpus, parent->effective_xcpus); if (adding) subparts_delta--; + new_prs = PRS_MEMBER; } else if (newmask) { /* * Empty cpumask is not allowed @@ -1940,37 +2000,24 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd, * newly deleted ones will be added back to effective_cpus. */ spin_lock_irq(&callback_lock); - if (adding) { - if (parent == &top_cpuset) - cpumask_andnot(subpartitions_cpus, - subpartitions_cpus, tmp->addmask); - /* - * Some of the CPUs in effective_xcpus might have been offlined. - */ - cpumask_or(parent->effective_cpus, - parent->effective_cpus, tmp->addmask); - cpumask_and(parent->effective_cpus, - parent->effective_cpus, cpu_active_mask); - } - if (deleting) { - if (parent == &top_cpuset) - cpumask_or(subpartitions_cpus, - subpartitions_cpus, tmp->delmask); - cpumask_andnot(parent->effective_cpus, - parent->effective_cpus, tmp->delmask); - } - - if (is_partition_valid(parent)) { - parent->nr_subparts += subparts_delta; - WARN_ON_ONCE(parent->nr_subparts < 0); - } - if (old_prs != new_prs) { cs->partition_root_state = new_prs; if (new_prs <= 0) cs->nr_subparts = 0; } + /* + * Adding to parent's effective_cpus means deletion CPUs from cs + * and vice versa. + */ + if (adding) + partition_xcpus_del(old_prs, parent, tmp->addmask); + if (deleting) + partition_xcpus_add(new_prs, parent, tmp->delmask); + if (is_partition_valid(parent)) { + parent->nr_subparts += subparts_delta; + WARN_ON_ONCE(parent->nr_subparts < 0); + } spin_unlock_irq(&callback_lock); if ((old_prs != new_prs) && (cmd == partcmd_update)) @@ -2948,6 +2995,7 @@ static int update_prstate(struct cpuset *cs, int new_prs) int err = PERR_NONE, old_prs = cs->partition_root_state; struct cpuset *parent = parent_cs(cs); struct tmpmasks tmpmask; + bool new_xcpus_state = false; if (old_prs == new_prs) return 0; @@ -2977,6 +3025,9 @@ static int update_prstate(struct cpuset *cs, int new_prs) goto out; if (!old_prs) { + enum partition_cmd cmd = (new_prs == PRS_ROOT) + ? partcmd_enable : partcmd_enablei; + /* * cpus_allowed cannot be empty. */ @@ -2985,19 +3036,18 @@ static int update_prstate(struct cpuset *cs, int new_prs) goto out; } - err = update_parent_effective_cpumask(cs, partcmd_enable, - NULL, &tmpmask); + err = update_parent_effective_cpumask(cs, cmd, NULL, &tmpmask); /* * If an attempt to become local partition root fails, * try to become a remote partition root instead. */ - if (err && remote_partition_enable(cs, &tmpmask)) + if (err && remote_partition_enable(cs, new_prs, &tmpmask)) err = 0; } else if (old_prs && new_prs) { /* * A change in load balance state only, no change in cpumasks. */ - ; + new_xcpus_state = true; } else { /* * Switching back to member is always allowed even if it @@ -3029,6 +3079,8 @@ static int update_prstate(struct cpuset *cs, int new_prs) WRITE_ONCE(cs->prs_err, err); if (!is_partition_valid(cs)) reset_partition_data(cs); + else if (new_xcpus_state) + partition_xcpus_newstate(old_prs, new_prs, cs->effective_xcpus); spin_unlock_irq(&callback_lock); /* Force update if switching back to member */ @@ -3386,6 +3438,7 @@ typedef enum { FILE_SUBPARTS_CPULIST, FILE_EXCLUSIVE_CPULIST, FILE_EFFECTIVE_XCPULIST, + FILE_ISOLATED_CPULIST, FILE_CPU_EXCLUSIVE, FILE_MEM_EXCLUSIVE, FILE_MEM_HARDWALL, @@ -3582,6 +3635,9 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v) case FILE_SUBPARTS_CPULIST: seq_printf(sf, "%*pbl\n", cpumask_pr_args(subpartitions_cpus)); break; + case FILE_ISOLATED_CPULIST: + seq_printf(sf, "%*pbl\n", cpumask_pr_args(isolated_cpus)); + break; default: ret = -EINVAL; } @@ -3875,6 +3931,13 @@ static struct cftype dfl_files[] = { .flags = CFTYPE_ONLY_ON_ROOT | CFTYPE_DEBUG, }, + { + .name = "cpus.isolated", + .seq_show = cpuset_common_seq_show, + .private = FILE_ISOLATED_CPULIST, + .flags = CFTYPE_ONLY_ON_ROOT | CFTYPE_DEBUG, + }, + { } /* terminate */ }; @@ -4194,6 +4257,7 @@ int __init cpuset_init(void) BUG_ON(!alloc_cpumask_var(&top_cpuset.effective_xcpus, GFP_KERNEL)); BUG_ON(!alloc_cpumask_var(&top_cpuset.exclusive_cpus, GFP_KERNEL)); BUG_ON(!zalloc_cpumask_var(&subpartitions_cpus, GFP_KERNEL)); + BUG_ON(!zalloc_cpumask_var(&isolated_cpus, GFP_KERNEL)); cpumask_setall(top_cpuset.cpus_allowed); nodes_setall(top_cpuset.mems_allowed);