/* * Read-Copy Update tracing for hierarchical implementation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, you can access it online at * http://www.gnu.org/licenses/gpl-2.0.html. * * Copyright IBM Corporation, 2008 * Author: Paul E. McKenney * * Papers: http://www.rdrop.com/users/paulmck/RCU * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU * */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/smp.h> #include <linux/rcupdate.h> #include <linux/interrupt.h> #include <linux/sched.h> #include <linux/atomic.h> #include <linux/bitops.h> #include <linux/completion.h> #include <linux/percpu.h> #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/debugfs.h> #include <linux/seq_file.h> #define RCU_TREE_NONCORE #include "tree.h" DECLARE_PER_CPU_SHARED_ALIGNED(unsigned long, rcu_qs_ctr); static int r_open(struct inode *inode, struct file *file, const struct seq_operations *op) { int ret = seq_open(file, op); if (!ret) { struct seq_file *m = (struct seq_file *)file->private_data; m->private = inode->i_private; } return ret; } static void *r_start(struct seq_file *m, loff_t *pos) { struct rcu_state *rsp = (struct rcu_state *)m->private; *pos = cpumask_next(*pos - 1, cpu_possible_mask); if ((*pos) < nr_cpu_ids) return per_cpu_ptr(rsp->rda, *pos); return NULL; } static void *r_next(struct seq_file *m, void *v, loff_t *pos) { (*pos)++; return r_start(m, pos); } static void r_stop(struct seq_file *m, void *v) { } static int show_rcubarrier(struct seq_file *m, void *v) { struct rcu_state *rsp = (struct rcu_state *)m->private; seq_printf(m, "bcc: %d bseq: %lu\n", atomic_read(&rsp->barrier_cpu_count), rsp->barrier_sequence); return 0; } static int rcubarrier_open(struct inode *inode, struct file *file) { return single_open(file, show_rcubarrier, inode->i_private); } static const struct file_operations rcubarrier_fops = { .owner = THIS_MODULE, .open = rcubarrier_open, .read = seq_read, .llseek = no_llseek, .release = single_release, }; #ifdef CONFIG_RCU_BOOST static char convert_kthread_status(unsigned int kthread_status) { if (kthread_status > RCU_KTHREAD_MAX) return '?'; return "SRWOY"[kthread_status]; } #endif /* #ifdef CONFIG_RCU_BOOST */ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) { long ql, qll; if (!rdp->beenonline) return; seq_printf(m, "%3d%cc=%ld g=%ld cnq=%d/%d:%d", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', ulong2long(rdp->completed), ulong2long(rdp->gpnum), rdp->cpu_no_qs.b.norm, rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu), rdp->core_needs_qs); seq_printf(m, " dt=%d/%llx/%d df=%lu", atomic_read(&rdp->dynticks->dynticks), rdp->dynticks->dynticks_nesting, rdp->dynticks->dynticks_nmi_nesting, rdp->dynticks_fqs); seq_printf(m, " of=%lu", rdp->offline_fqs); rcu_nocb_q_lengths(rdp, &ql, &qll); qll += rdp->qlen_lazy; ql += rdp->qlen; seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c", qll, ql, ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] != rdp->nxttail[RCU_NEXT_TAIL]], ".R"[rdp->nxttail[RCU_WAIT_TAIL] != rdp->nxttail[RCU_NEXT_READY_TAIL]], ".W"[rdp->nxttail[RCU_DONE_TAIL] != rdp->nxttail[RCU_WAIT_TAIL]], ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]); #ifdef CONFIG_RCU_BOOST seq_printf(m, " kt=%d/%c ktl=%x", per_cpu(rcu_cpu_has_work, rdp->cpu), convert_kthread_status(per_cpu(rcu_cpu_kthread_status, rdp->cpu)), per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff); #endif /* #ifdef CONFIG_RCU_BOOST */ seq_printf(m, " b=%ld", rdp->blimit); seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu\n", rdp->n_cbs_invoked, rdp->n_nocbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } static int show_rcudata(struct seq_file *m, void *v) { print_one_rcu_data(m, (struct rcu_data *)v); return 0; } static const struct seq_operations rcudate_op = { .start = r_start, .next = r_next, .stop = r_stop, .show = show_rcudata, }; static int rcudata_open(struct inode *inode, struct file *file) { return r_open(inode, file, &rcudate_op); } static const struct file_operations rcudata_fops = { .owner = THIS_MODULE, .open = rcudata_open, .read = seq_read, .llseek = no_llseek, .release = seq_release, }; static int show_rcuexp(struct seq_file *m, void *v) { int cpu; struct rcu_state *rsp = (struct rcu_state *)m->private; struct rcu_data *rdp; unsigned long s0 = 0, s1 = 0, s2 = 0, s3 = 0; for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(rsp->rda, cpu); s0 += atomic_long_read(&rdp->exp_workdone0); s1 += atomic_long_read(&rdp->exp_workdone1); s2 += atomic_long_read(&rdp->exp_workdone2); s3 += atomic_long_read(&rdp->exp_workdone3); } seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", rsp->expedited_sequence, s0, s1, s2, s3, atomic_long_read(&rsp->expedited_normal), atomic_read(&rsp->expedited_need_qs), rsp->expedited_sequence / 2); return 0; } static int rcuexp_open(struct inode *inode, struct file *file) { return single_open(file, show_rcuexp, inode->i_private); } static const struct file_operations rcuexp_fops = { .owner = THIS_MODULE, .open = rcuexp_open, .read = seq_read, .llseek = no_llseek, .release = single_release, }; #ifdef CONFIG_RCU_BOOST static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp) { seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ", rnp->grplo, rnp->grphi, "T."[list_empty(&rnp->blkd_tasks)], "N."[!rnp->gp_tasks], "E."[!rnp->exp_tasks], "B."[!rnp->boost_tasks], convert_kthread_status(rnp->boost_kthread_status), rnp->n_tasks_boosted, rnp->n_exp_boosts, rnp->n_normal_boosts); seq_printf(m, "j=%04x bt=%04x\n", (int)(jiffies & 0xffff), (int)(rnp->boost_time & 0xffff)); seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n", rnp->n_balk_blkd_tasks, rnp->n_balk_exp_gp_tasks, rnp->n_balk_boost_tasks, rnp->n_balk_notblocked, rnp->n_balk_notyet, rnp->n_balk_nos); } static int show_rcu_node_boost(struct seq_file *m, void *unused) { struct rcu_node *rnp; rcu_for_each_leaf_node(&rcu_preempt_state, rnp) print_one_rcu_node_boost(m, rnp); return 0; } static int rcu_node_boost_open(struct inode *inode, struct file *file) { return single_open(file, show_rcu_node_boost, NULL); } static const struct file_operations rcu_node_boost_fops = { .owner = THIS_MODULE, .open = rcu_node_boost_open, .read = seq_read, .llseek = no_llseek, .release = single_release, }; #endif /* #ifdef CONFIG_RCU_BOOST */ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp) { unsigned long gpnum; int level = 0; struct rcu_node *rnp; gpnum = rsp->gpnum; seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ", ulong2long(rsp->completed), ulong2long(gpnum), rsp->gp_state, (long)(rsp->jiffies_force_qs - jiffies), (int)(jiffies & 0xffff)); seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n", rsp->n_force_qs, rsp->n_force_qs_ngp, rsp->n_force_qs - rsp->n_force_qs_ngp, READ_ONCE(rsp->n_force_qs_lh), rsp->qlen_lazy, rsp->qlen); for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) { if (rnp->level != level) { seq_puts(m, "\n"); level = rnp->level; } seq_printf(m, "%lx/%lx->%lx %c%c>%c %d:%d ^%d ", rnp->qsmask, rnp->qsmaskinit, rnp->qsmaskinitnext, ".G"[rnp->gp_tasks != NULL], ".E"[rnp->exp_tasks != NULL], ".T"[!list_empty(&rnp->blkd_tasks)], rnp->grplo, rnp->grphi, rnp->grpnum); } seq_puts(m, "\n"); } static int show_rcuhier(struct seq_file *m, void *v) { struct rcu_state *rsp = (struct rcu_state *)m->private; print_one_rcu_state(m, rsp); return 0; } static int rcuhier_open(struct inode *inode, struct file *file) { return single_open(file, show_rcuhier, inode->i_private); } static const struct file_operations rcuhier_fops = { .owner = THIS_MODULE, .open = rcuhier_open, .read = seq_read, .llseek = no_llseek, .release = single_release, }; static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp) { unsigned long flags; unsigned long completed; unsigned long gpnum; unsigned long gpage; unsigned long gpmax; struct rcu_node *rnp = &rsp->node[0]; raw_spin_lock_irqsave_rcu_node(rnp, flags); completed = READ_ONCE(rsp->completed); gpnum = READ_ONCE(rsp->gpnum); if (completed == gpnum) gpage = 0; else gpage = jiffies - rsp->gp_start; gpmax = rsp->gp_max; raw_spin_unlock_irqrestore(&rnp->lock, flags); seq_printf(m, "completed=%ld gpnum=%ld age=%ld max=%ld\n", ulong2long(completed), ulong2long(gpnum), gpage, gpmax); } static int show_rcugp(struct seq_file *m, void *v) { struct rcu_state *rsp = (struct rcu_state *)m->private; show_one_rcugp(m, rsp); return 0; } static int rcugp_open(struct inode *inode, struct file *file) { return single_open(file, show_rcugp, inode->i_private); } static const struct file_operations rcugp_fops = { .owner = THIS_MODULE, .open = rcugp_open, .read = seq_read, .llseek = no_llseek, .release = single_release, }; static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) { if (!rdp->beenonline) return; seq_printf(m, "%3d%cnp=%ld ", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', rdp->n_rcu_pending); seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ", rdp->n_rp_core_needs_qs, rdp->n_rp_report_qs, rdp->n_rp_cb_ready, rdp->n_rp_cpu_needs_gp); seq_printf(m, "gpc=%ld gps=%ld nn=%ld ndw%ld\n", rdp->n_rp_gp_completed, rdp->n_rp_gp_started, rdp->n_rp_nocb_defer_wakeup, rdp->n_rp_need_nothing); } static int show_rcu_pending(struct seq_file *m, void *v) { print_one_rcu_pending(m, (struct rcu_data *)v); return 0; } static const struct seq_operations rcu_pending_op = { .start = r_start, .next = r_next, .stop = r_stop, .show = show_rcu_pending, }; static int rcu_pending_open(struct inode *inode, struct file *file) { return r_open(inode, file, &rcu_pending_op); } static const struct file_operations rcu_pending_fops = { .owner = THIS_MODULE, .open = rcu_pending_open, .read = seq_read, .llseek = no_llseek, .release = seq_release, }; static int show_rcutorture(struct seq_file *m, void *unused) { seq_printf(m, "rcutorture test sequence: %lu %s\n", rcutorture_testseq >> 1, (rcutorture_testseq & 0x1) ? "(test in progress)" : ""); seq_printf(m, "rcutorture update version number: %lu\n", rcutorture_vernum); return 0; } static int rcutorture_open(struct inode *inode, struct file *file) { return single_open(file, show_rcutorture, NULL); } static const struct file_operations rcutorture_fops = { .owner = THIS_MODULE, .open = rcutorture_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static struct dentry *rcudir; static int __init rcutree_trace_init(void) { struct rcu_state *rsp; struct dentry *retval; struct dentry *rspdir; rcudir = debugfs_create_dir("rcu", NULL); if (!rcudir) goto free_out; for_each_rcu_flavor(rsp) { rspdir = debugfs_create_dir(rsp->name, rcudir); if (!rspdir) goto free_out; retval = debugfs_create_file("rcudata", 0444, rspdir, rsp, &rcudata_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcuexp", 0444, rspdir, rsp, &rcuexp_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcu_pending", 0444, rspdir, rsp, &rcu_pending_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcubarrier", 0444, rspdir, rsp, &rcubarrier_fops); if (!retval) goto free_out; #ifdef CONFIG_RCU_BOOST if (rsp == &rcu_preempt_state) { retval = debugfs_create_file("rcuboost", 0444, rspdir, NULL, &rcu_node_boost_fops); if (!retval) goto free_out; } #endif retval = debugfs_create_file("rcugp", 0444, rspdir, rsp, &rcugp_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcuhier", 0444, rspdir, rsp, &rcuhier_fops); if (!retval) goto free_out; } retval = debugfs_create_file("rcutorture", 0444, rcudir, NULL, &rcutorture_fops); if (!retval) goto free_out; return 0; free_out: debugfs_remove_recursive(rcudir); return 1; } device_initcall(rcutree_trace_init);