diff options
Diffstat (limited to 'kernel/rcutree_trace.c')
| -rw-r--r-- | kernel/rcutree_trace.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c new file mode 100644 index 00000000..ed459ede --- /dev/null +++ b/kernel/rcutree_trace.c @@ -0,0 +1,504 @@ +/* + * 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 <linux/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 + +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 pgp=%lu qp=%d", + rdp->cpu, + cpu_is_offline(rdp->cpu) ? '!' : ' ', + rdp->completed, rdp->gpnum, + rdp->passed_quiesce, rdp->passed_quiesce_gpnum, + rdp->qs_pending); + 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); + seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c", + rdp->qlen_lazy, 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_quiesce, rdp->passed_quiesce_gpnum, + rdp->qs_pending); + seq_printf(m, ",%d,%llx,%d,%lu", + atomic_read(&rdp->dynticks->dynticks), + rdp->dynticks->dynticks_nesting, + rdp->dynticks->dynticks_nmi_nesting, + rdp->dynticks_fqs); + seq_printf(m, ",%lu", rdp->offline_fqs); + seq_printf(m, ",%ld,%ld,\"%c%c%c%c\"", rdp->qlen_lazy, 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\",\"pgp\",\"pq\","); + seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\","); + seq_puts(m, "\"of\",\"qll\",\"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->fqs_state, + (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"); |