Commit-ID: f3cbeacaa06e2b8c2f3ce8531e9aa3fe1f2762cd Gitweb: http://git.kernel.org/tip/f3cbeacaa06e2b8c2f3ce8531e9aa3fe1f2762cd Author: Vikas Shivappa <vikas.shiva...@linux.intel.com> AuthorDate: Tue, 25 Jul 2017 14:14:40 -0700 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Tue, 1 Aug 2017 22:41:27 +0200
x86/intel_rdt/cqm: Add rmdir support Resource groups (ctrl_mon and monitor groups) are represented by directories in resctrl fs. Add support to remove the directories. When a ctrl_mon directory is removed all the cpus and tasks are assigned back to the root rdtgroup. When a monitor group is removed the cpus and tasks are returned to the parent control group. Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: ravi.v.shan...@intel.com Cc: tony.l...@intel.com Cc: fenghua...@intel.com Cc: pet...@infradead.org Cc: eran...@google.com Cc: vikas.shiva...@intel.com Cc: a...@linux.intel.com Cc: davi...@google.com Cc: reinette.cha...@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-22-git-send-email-vikas.shiva...@linux.intel.com --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 90 ++++++++++++++++++++++++++++++-- 1 file changed, 86 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 3b62287..e619081 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -1130,6 +1130,18 @@ static int reset_all_ctrls(struct rdt_resource *r) return 0; } +static bool is_closid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (rdt_alloc_capable && + (r->type == RDTCTRL_GROUP) && (t->closid == r->closid)); +} + +static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (rdt_mon_capable && + (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid)); +} + /* * Move tasks from one to the other group. If @from is NULL, then all tasks * in the systems are moved unconditionally (used for teardown). @@ -1145,8 +1157,11 @@ static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, read_lock(&tasklist_lock); for_each_process_thread(p, t) { - if (!from || t->closid == from->closid) { + if (!from || is_closid_match(t, from) || + is_rmid_match(t, from)) { t->closid = to->closid; + t->rmid = to->mon.rmid; + #ifdef CONFIG_SMP /* * This is safe on x86 w/o barriers as the ordering @@ -1165,6 +1180,19 @@ static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, read_unlock(&tasklist_lock); } +static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) +{ + struct rdtgroup *sentry, *stmp; + struct list_head *head; + + head = &rdtgrp->mon.crdtgrp_list; + list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) { + free_rmid(sentry->mon.rmid); + list_del(&sentry->mon.crdtgrp_list); + kfree(sentry); + } +} + /* * Forcibly remove all of subdirectories under root. */ @@ -1565,6 +1593,44 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, return -EPERM; } +static int rdtgroup_rmdir_mon(struct kernfs_node *kn, struct rdtgroup *rdtgrp, + cpumask_var_t tmpmask) +{ + struct rdtgroup *prdtgrp = rdtgrp->mon.parent; + int cpu; + + /* Give any tasks back to the parent group */ + rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask); + + /* Update per cpu rmid of the moved CPUs first */ + for_each_cpu(cpu, &rdtgrp->cpu_mask) + per_cpu(rdt_cpu_default.rmid, cpu) = prdtgrp->mon.rmid; + /* + * Update the MSR on moved CPUs and CPUs which have moved + * task running on them. + */ + cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); + update_closid_rmid(tmpmask, NULL); + + rdtgrp->flags = RDT_DELETED; + free_rmid(rdtgrp->mon.rmid); + + /* + * Remove the rdtgrp from the parent ctrl_mon group's list + */ + WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); + list_del(&rdtgrp->mon.crdtgrp_list); + + /* + * one extra hold on this, will drop when we kfree(rdtgrp) + * in rdtgroup_kn_unlock() + */ + kernfs_get(kn); + kernfs_remove(rdtgrp->kn); + + return 0; +} + static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) { @@ -1577,9 +1643,12 @@ static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp, cpumask_or(&rdtgroup_default.cpu_mask, &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); - /* Update per cpu closid of the moved CPUs first */ - for_each_cpu(cpu, &rdtgrp->cpu_mask) + /* Update per cpu closid and rmid of the moved CPUs first */ + for_each_cpu(cpu, &rdtgrp->cpu_mask) { per_cpu(rdt_cpu_default.closid, cpu) = rdtgroup_default.closid; + per_cpu(rdt_cpu_default.rmid, cpu) = rdtgroup_default.mon.rmid; + } + /* * Update the MSR on moved CPUs and CPUs which have moved * task running on them. @@ -1589,6 +1658,13 @@ static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp, rdtgrp->flags = RDT_DELETED; closid_free(rdtgrp->closid); + free_rmid(rdtgrp->mon.rmid); + + /* + * Free all the child monitor group rmids. + */ + free_all_child_rdtgrp(rdtgrp); + list_del(&rdtgrp->rdtgroup_list); /* @@ -1619,10 +1695,16 @@ static int rdtgroup_rmdir(struct kernfs_node *kn) /* * If the rdtgroup is a ctrl_mon group and parent directory - * is the root directory, remove the ctrl group. + * is the root directory, remove the ctrl_mon group. + * + * If the rdtgroup is a mon group and parent directory + * is a valid "mon_groups" directory, remove the mon group. */ if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn) ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask); + else if (rdtgrp->type == RDTMON_GROUP && + is_mon_groups(parent_kn, kn->name)) + ret = rdtgroup_rmdir_mon(kn, rdtgrp, tmpmask); else ret = -EPERM;
