/* * Read-Copy Update tracing for classic 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, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright IBM Corporation, 2008 * * 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 <asm/atomic.h> #include <linux/bitops.h> #include <linux/module.h> #include <linux/completion.h> #include <linux/moduleparam.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 "rcutree.h" #ifdef CONFIG_RCU_BOOST DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status); DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu); DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); DECLARE_PER_CPU(char, rcu_cpu_has_work); 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) { if (!rdp->beenonline) return; seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', rdp->completed, rdp->gpnum, rdp->passed_quiesc, rdp->passed_quiesc_completed, rdp->qs_pending); #ifdef CONFIG_NO_HZ seq_printf(m, " dt=%d/%d/%d df=%lu", atomic_read(&rdp->dynticks->dynticks), rdp->dynticks->dynticks_nesting, rdp->dynticks->dynticks_nmi_nesting, rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi); seq_printf(m, " ql=%ld qs=%c%c%c%c", rdp->qlen, ".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/%d 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_cpu, 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 co=%lu ca=%lu\n", rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } #define PRINT_RCU_DATA(name, func, m) \ do { \ int _p_r_d_i; \ \ for_each_possible_cpu(_p_r_d_i) \ func(m, &per_cpu(name, _p_r_d_i)); \ } while (0) static int show_rcudata(struct seq_file *m, void *unused) { #ifdef CONFIG_TREE_PREEMPT_RCU seq_puts(m, "rcu_preempt:\n"); PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ seq_puts(m, "rcu_sched:\n"); PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m); seq_puts(m, "rcu_bh:\n"); PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m); return 0; } static int rcudata_open(struct inode *inode, struct file *file) { return single_open(file, show_rcudata, NULL); } static const struct file_operations rcudata_fops = { .owner = THIS_MODULE, .open = rcudata_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp) { if (!rdp->beenonline) return; seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d", rdp->cpu, cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"", rdp->completed, rdp->gpnum, rdp->passed_quiesc, rdp->passed_quiesc_completed, rdp->qs_pending); #ifdef CONFIG_NO_HZ seq_printf(m, ",%d,%d,%d,%lu", atomic_read(&rdp->dynticks->dynticks), rdp->dynticks->dynticks_nesting, rdp->dynticks->dynticks_nmi_nesting, rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi); seq_printf(m, ",%ld,\"%c%c%c%c\"", rdp->qlen, ".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, ",%d,\"%c\"", per_cpu(rcu_cpu_has_work, rdp->cpu), convert_kthread_status(per_cpu(rcu_cpu_kthread_status, rdp->cpu))); #endif /* #ifdef CONFIG_RCU_BOOST */ seq_printf(m, ",%ld", rdp->blimit); seq_printf(m, ",%lu,%lu,%lu\n", rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } static int show_rcudata_csv(struct seq_file *m, void *unused) { seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\","); #ifdef CONFIG_NO_HZ seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\","); #endif /* #ifdef CONFIG_NO_HZ */ seq_puts(m, "\"of\",\"ri\",\"ql\",\"qs\""); #ifdef CONFIG_RCU_BOOST seq_puts(m, "\"kt\",\"ktl\""); #endif /* #ifdef CONFIG_RCU_BOOST */ seq_puts(m, ",\"b\",\"ci\",\"co\",\"ca\"\n"); #ifdef CONFIG_TREE_PREEMPT_RCU seq_puts(m, "\"rcu_preempt:\"\n"); PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ seq_puts(m, "\"rcu_sched:\"\n"); PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m); seq_puts(m, "\"rcu_bh:\"\n"); PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m); return 0; } static int rcudata_csv_open(struct inode *inode, struct file *file) { return single_open(file, show_rcudata_csv, NULL); } static const struct file_operations rcudata_csv_fops = { .owner = THIS_MODULE, .open = rcudata_csv_open, .read = seq_read, .llseek = seq_lseek, .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 " "j=%04x bt=%04x\n", 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, (int)(jiffies & 0xffff), (int)(rnp->boost_time & 0xffff)); seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n", " balk", 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 = seq_lseek, .release = single_release, }; /* * Create the rcuboost debugfs entry. Standard error return. */ static int rcu_boost_trace_create_file(struct dentry *rcudir) { return !debugfs_create_file("rcuboost", 0444, rcudir, NULL, &rcu_node_boost_fops); } #else /* #ifdef CONFIG_RCU_BOOST */ static int rcu_boost_trace_create_file(struct dentry *rcudir) { return 0; /* There cannot be an error if we didn't create it! */ } #endif /* #else #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=%lu g=%lu s=%d jfq=%ld j=%x " "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n", rsp->completed, gpnum, rsp->signaled, (long)(rsp->jiffies_force_qs - jiffies), (int)(jiffies & 0xffff), rsp->n_force_qs, rsp->n_force_qs_ngp, rsp->n_force_qs - rsp->n_force_qs_ngp, rsp->n_force_qs_lh); for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) { if (rnp->level != level) { seq_puts(m, "\n"); level = rnp->level; } seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ", rnp->qsmask, rnp->qsmaskinit, ".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 *unused) { #ifdef CONFIG_TREE_PREEMPT_RCU seq_puts(m, "rcu_preempt:\n"); print_one_rcu_state(m, &rcu_preempt_state); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ seq_puts(m, "rcu_sched:\n"); print_one_rcu_state(m, &rcu_sched_state); seq_puts(m, "rcu_bh:\n"); print_one_rcu_state(m, &rcu_bh_state); return 0; } static int rcuhier_open(struct inode *inode, struct file *file) { return single_open(file, show_rcuhier, NULL); } static const struct file_operations rcuhier_fops = { .owner = THIS_MODULE, .open = rcuhier_open, .read = seq_read, .llseek = seq_lseek, .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(&rnp->lock, flags); completed = rsp->completed; gpnum = rsp->gpnum; if (rsp->completed == rsp->gpnum) gpage = 0; else gpage = jiffies - rsp->gp_start; gpmax = rsp->gp_max; raw_spin_unlock_irqrestore(&rnp->lock, flags); seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n", rsp->name, completed, gpnum, gpage, gpmax); } static int show_rcugp(struct seq_file *m, void *unused) { #ifdef CONFIG_TREE_PREEMPT_RCU show_one_rcugp(m, &rcu_preempt_state); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ show_one_rcugp(m, &rcu_sched_state); show_one_rcugp(m, &rcu_bh_state); return 0; } static int rcugp_open(struct inode *inode, struct file *file) { return single_open(file, show_rcugp, NULL); } static const struct file_operations rcugp_fops = { .owner = THIS_MODULE, .open = rcugp_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) { seq_printf(m, "%3d%cnp=%ld " "qsp=%ld rpq=%ld cbr=%ld cng=%ld " "gpc=%ld gps=%ld nf=%ld nn=%ld\n", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', rdp->n_rcu_pending, rdp->n_rp_qs_pending, rdp->n_rp_report_qs, rdp->n_rp_cb_ready, rdp->n_rp_cpu_needs_gp, rdp->n_rp_gp_completed, rdp->n_rp_gp_started, rdp->n_rp_need_fqs, rdp->n_rp_need_nothing); } static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp) { int cpu; struct rcu_data *rdp; for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(rsp->rda, cpu); if (rdp->beenonline) print_one_rcu_pending(m, rdp); } } static int show_rcu_pending(struct seq_file *m, void *unused) { #ifdef CONFIG_TREE_PREEMPT_RCU seq_puts(m, "rcu_preempt:\n"); print_rcu_pendings(m, &rcu_preempt_state); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ seq_puts(m, "rcu_sched:\n"); print_rcu_pendings(m, &rcu_sched_state); seq_puts(m, "rcu_bh:\n"); print_rcu_pendings(m, &rcu_bh_state); return 0; } static int rcu_pending_open(struct inode *inode, struct file *file) { return single_open(file, show_rcu_pending, NULL); } static const struct file_operations rcu_pending_fops = { .owner = THIS_MODULE, .open = rcu_pending_open, .read = seq_read, .llseek = seq_lseek, .release = single_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 dentry *retval; rcudir = debugfs_create_dir("rcu", NULL); if (!rcudir) goto free_out; retval = debugfs_create_file("rcudata", 0444, rcudir, NULL, &rcudata_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcudata.csv", 0444, rcudir, NULL, &rcudata_csv_fops); if (!retval) goto free_out; if (rcu_boost_trace_create_file(rcudir)) goto free_out; retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcuhier", 0444, rcudir, NULL, &rcuhier_fops); if (!retval) goto free_out; retval = debugfs_create_file("rcu_pending", 0444, rcudir, NULL, &rcu_pending_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; } static void __exit rcutree_trace_cleanup(void) { debugfs_remove_recursive(rcudir); } module_init(rcutree_trace_init); module_exit(rcutree_trace_cleanup); MODULE_AUTHOR("Paul E. McKenney"); MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation"); MODULE_LICENSE("GPL");