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 <[email protected]> --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 110 +++++++++++++++++++++++++++---- 1 file changed, 99 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 9377bcd..6131508 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -1164,6 +1164,18 @@ 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_enabled && + (r->type == RDTCTRL_GROUP) && (t->closid == r->closid)); +} + +static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (rdt_mon_features && + (r->type == RDTMON_GROUP) && (t->rmid == r->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). @@ -1179,8 +1191,11 @@ 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->rmid; + #ifdef CONFIG_SMP /* * This is safe on x86 w/o barriers as the ordering @@ -1402,6 +1417,7 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn, struct rdtgroup *pr, kernfs_remove(kn); return ret; } + /* * Common code for ctrl_mon and monitor group mkdir. * The caller needs to unlock the global mutex upon success. @@ -1588,20 +1604,57 @@ static int rdtgroup_mkdir(struct kernfs_node *pkn, const char *name, return -EPERM; } -static int rdtgroup_rmdir(struct kernfs_node *kn) +static int rdtgroup_rmdir_mon(struct kernfs_node *kn, struct rdtgroup *rdtgrp) { - int ret, cpu, closid = rdtgroup_default.closid; - struct rdtgroup *rdtgrp; + struct rdtgroup *prdtgrp = rdtgrp->parent; cpumask_var_t tmpmask; + int cpu; if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) return -ENOMEM; - rdtgrp = rdtgroup_kn_lock_live(kn); - if (!rdtgrp) { - ret = -EPERM; - goto out; - } + /* 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(cpu_rmid, cpu) = prdtgrp->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->rmid); + + /* + * Remove your rmid from the parent ctrl groups list + */ + WARN_ON(list_empty(&prdtgrp->crdtgrp_list)); + list_del(&rdtgrp->crdtgrp_list); + + /* + * one extra hold on this, will drop when we kfree(rdtgrp) + * in rdtgroup_kn_unlock() + */ + kernfs_get(kn); + kernfs_remove(rdtgrp->kn); + free_cpumask_var(tmpmask); + + return 0; +} + +static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp) +{ + int cpu, closid = rdtgroup_default.closid; + struct rdtgroup *entry, *tmp; + struct list_head *llist; + cpumask_var_t tmpmask; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; /* Give any tasks back to the default group */ rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); @@ -1622,6 +1675,18 @@ static int rdtgroup_rmdir(struct kernfs_node *kn) rdtgrp->flags = RDT_DELETED; closid_free(rdtgrp->closid); + free_rmid(rdtgrp->rmid); + + /* + * Free all the child monitor group rmids. + */ + llist = &rdtgrp->crdtgrp_list; + list_for_each_entry_safe(entry, tmp, llist, crdtgrp_list) { + free_rmid(entry->rmid); + list_del(&entry->crdtgrp_list); + kfree(entry); + } + list_del(&rdtgrp->rdtgroup_list); /* @@ -1630,10 +1695,33 @@ static int rdtgroup_rmdir(struct kernfs_node *kn) */ kernfs_get(kn); kernfs_remove(rdtgrp->kn); - ret = 0; + free_cpumask_var(tmpmask); + + return 0; +} + +static int rdtgroup_rmdir(struct kernfs_node *kn) +{ + struct kernfs_node *parent_kn = kn->parent; + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(kn); + if (!rdtgrp) { + ret = -EPERM; + goto out; + } + + if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn) + ret = rdtgroup_rmdir_ctrl(kn, rdtgrp); + else if (rdtgrp->type == RDTMON_GROUP && + !strcmp(parent_kn->name, "mon_groups")) + ret = rdtgroup_rmdir_mon(kn, rdtgrp); + else + ret = -EPERM; + out: rdtgroup_kn_unlock(kn); - free_cpumask_var(tmpmask); return ret; } -- 1.9.1
