15ba0ba860
This commit adds the age in jiffies of the current grace period along with the duration in jiffies of the longest grace period since boot to the rcu/rcugp debugfs file. It also adds an additional "O" state to kthread tracing to differentiate between the kthread waiting due to having nothing to do on the one hand and waiting due to being on the wrong CPU on the other hand. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
500 lines
14 KiB
C
500 lines
14 KiB
C
/*
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* Read-Copy Update tracing for classic implementation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright IBM Corporation, 2008
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*
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* Papers: http://www.rdrop.com/users/paulmck/RCU
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*
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* For detailed explanation of Read-Copy Update mechanism see -
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* Documentation/RCU
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*
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/smp.h>
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#include <linux/rcupdate.h>
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#include <linux/interrupt.h>
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#include <linux/sched.h>
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#include <asm/atomic.h>
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#include <linux/bitops.h>
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#include <linux/module.h>
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#include <linux/completion.h>
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#include <linux/moduleparam.h>
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#include <linux/percpu.h>
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#include <linux/notifier.h>
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#include <linux/cpu.h>
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#include <linux/mutex.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#define RCU_TREE_NONCORE
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#include "rcutree.h"
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DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
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DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu);
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DECLARE_PER_CPU(char, rcu_cpu_has_work);
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static char convert_kthread_status(unsigned int kthread_status)
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{
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if (kthread_status > RCU_KTHREAD_MAX)
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return '?';
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return "SRWOY"[kthread_status];
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}
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static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
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{
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if (!rdp->beenonline)
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return;
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seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
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rdp->cpu,
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cpu_is_offline(rdp->cpu) ? '!' : ' ',
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rdp->completed, rdp->gpnum,
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rdp->passed_quiesc, rdp->passed_quiesc_completed,
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rdp->qs_pending);
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#ifdef CONFIG_NO_HZ
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seq_printf(m, " dt=%d/%d/%d df=%lu",
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atomic_read(&rdp->dynticks->dynticks),
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rdp->dynticks->dynticks_nesting,
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rdp->dynticks->dynticks_nmi_nesting,
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rdp->dynticks_fqs);
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#endif /* #ifdef CONFIG_NO_HZ */
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seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
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seq_printf(m, " ql=%ld qs=%c%c%c%c kt=%d/%c/%d b=%ld",
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rdp->qlen,
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".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
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rdp->nxttail[RCU_NEXT_TAIL]],
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".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
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rdp->nxttail[RCU_NEXT_READY_TAIL]],
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".W"[rdp->nxttail[RCU_DONE_TAIL] !=
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rdp->nxttail[RCU_WAIT_TAIL]],
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".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]],
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per_cpu(rcu_cpu_has_work, rdp->cpu),
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convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
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rdp->cpu)),
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per_cpu(rcu_cpu_kthread_cpu, rdp->cpu),
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rdp->blimit);
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seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
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rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
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}
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#define PRINT_RCU_DATA(name, func, m) \
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do { \
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int _p_r_d_i; \
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\
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for_each_possible_cpu(_p_r_d_i) \
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func(m, &per_cpu(name, _p_r_d_i)); \
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} while (0)
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static int show_rcudata(struct seq_file *m, void *unused)
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{
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#ifdef CONFIG_TREE_PREEMPT_RCU
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seq_puts(m, "rcu_preempt:\n");
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PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
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#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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seq_puts(m, "rcu_sched:\n");
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PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
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seq_puts(m, "rcu_bh:\n");
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PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
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return 0;
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}
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static int rcudata_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcudata, NULL);
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}
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static const struct file_operations rcudata_fops = {
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.owner = THIS_MODULE,
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.open = rcudata_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
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{
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if (!rdp->beenonline)
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return;
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seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
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rdp->cpu,
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cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
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rdp->completed, rdp->gpnum,
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rdp->passed_quiesc, rdp->passed_quiesc_completed,
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rdp->qs_pending);
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#ifdef CONFIG_NO_HZ
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seq_printf(m, ",%d,%d,%d,%lu",
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atomic_read(&rdp->dynticks->dynticks),
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rdp->dynticks->dynticks_nesting,
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rdp->dynticks->dynticks_nmi_nesting,
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rdp->dynticks_fqs);
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#endif /* #ifdef CONFIG_NO_HZ */
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seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
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seq_printf(m, ",%ld,\"%c%c%c%c\",%d,\"%c\",%ld", rdp->qlen,
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".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
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rdp->nxttail[RCU_NEXT_TAIL]],
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".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
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rdp->nxttail[RCU_NEXT_READY_TAIL]],
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".W"[rdp->nxttail[RCU_DONE_TAIL] !=
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rdp->nxttail[RCU_WAIT_TAIL]],
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".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]],
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per_cpu(rcu_cpu_has_work, rdp->cpu),
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convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
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rdp->cpu)),
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rdp->blimit);
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seq_printf(m, ",%lu,%lu,%lu\n",
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rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
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}
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static int show_rcudata_csv(struct seq_file *m, void *unused)
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{
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seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
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#ifdef CONFIG_NO_HZ
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seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
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#endif /* #ifdef CONFIG_NO_HZ */
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seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
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#ifdef CONFIG_TREE_PREEMPT_RCU
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seq_puts(m, "\"rcu_preempt:\"\n");
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PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
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#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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seq_puts(m, "\"rcu_sched:\"\n");
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PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
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seq_puts(m, "\"rcu_bh:\"\n");
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PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
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return 0;
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}
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static int rcudata_csv_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcudata_csv, NULL);
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}
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static const struct file_operations rcudata_csv_fops = {
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.owner = THIS_MODULE,
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.open = rcudata_csv_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#ifdef CONFIG_RCU_BOOST
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static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
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{
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seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu "
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"j=%04x bt=%04x\n",
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rnp->grplo, rnp->grphi,
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"T."[list_empty(&rnp->blkd_tasks)],
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"N."[!rnp->gp_tasks],
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"E."[!rnp->exp_tasks],
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"B."[!rnp->boost_tasks],
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convert_kthread_status(rnp->boost_kthread_status),
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rnp->n_tasks_boosted, rnp->n_exp_boosts,
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rnp->n_normal_boosts,
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(int)(jiffies & 0xffff),
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(int)(rnp->boost_time & 0xffff));
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seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
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" balk",
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rnp->n_balk_blkd_tasks,
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rnp->n_balk_exp_gp_tasks,
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rnp->n_balk_boost_tasks,
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rnp->n_balk_notblocked,
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rnp->n_balk_notyet,
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rnp->n_balk_nos);
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}
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static int show_rcu_node_boost(struct seq_file *m, void *unused)
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{
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struct rcu_node *rnp;
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rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
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print_one_rcu_node_boost(m, rnp);
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return 0;
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}
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static int rcu_node_boost_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcu_node_boost, NULL);
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}
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static const struct file_operations rcu_node_boost_fops = {
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.owner = THIS_MODULE,
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.open = rcu_node_boost_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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/*
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* Create the rcuboost debugfs entry. Standard error return.
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*/
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static int rcu_boost_trace_create_file(struct dentry *rcudir)
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{
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return !debugfs_create_file("rcuboost", 0444, rcudir, NULL,
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&rcu_node_boost_fops);
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}
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#else /* #ifdef CONFIG_RCU_BOOST */
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static int rcu_boost_trace_create_file(struct dentry *rcudir)
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{
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return 0; /* There cannot be an error if we didn't create it! */
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}
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#endif /* #else #ifdef CONFIG_RCU_BOOST */
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static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
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{
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unsigned long gpnum;
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int level = 0;
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struct rcu_node *rnp;
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gpnum = rsp->gpnum;
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seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
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"nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
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rsp->completed, gpnum, rsp->signaled,
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(long)(rsp->jiffies_force_qs - jiffies),
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(int)(jiffies & 0xffff),
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rsp->n_force_qs, rsp->n_force_qs_ngp,
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rsp->n_force_qs - rsp->n_force_qs_ngp,
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rsp->n_force_qs_lh);
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for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
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if (rnp->level != level) {
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seq_puts(m, "\n");
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level = rnp->level;
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}
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seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ",
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rnp->qsmask, rnp->qsmaskinit,
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".G"[rnp->gp_tasks != NULL],
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".E"[rnp->exp_tasks != NULL],
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".T"[!list_empty(&rnp->blkd_tasks)],
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rnp->grplo, rnp->grphi, rnp->grpnum);
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}
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seq_puts(m, "\n");
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}
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static int show_rcuhier(struct seq_file *m, void *unused)
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{
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#ifdef CONFIG_TREE_PREEMPT_RCU
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seq_puts(m, "rcu_preempt:\n");
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print_one_rcu_state(m, &rcu_preempt_state);
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#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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seq_puts(m, "rcu_sched:\n");
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print_one_rcu_state(m, &rcu_sched_state);
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seq_puts(m, "rcu_bh:\n");
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print_one_rcu_state(m, &rcu_bh_state);
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return 0;
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}
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static int rcuhier_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcuhier, NULL);
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}
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static const struct file_operations rcuhier_fops = {
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.owner = THIS_MODULE,
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.open = rcuhier_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
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{
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unsigned long flags;
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unsigned long completed;
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unsigned long gpnum;
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unsigned long gpage;
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unsigned long gpmax;
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struct rcu_node *rnp = &rsp->node[0];
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raw_spin_lock_irqsave(&rnp->lock, flags);
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completed = rsp->completed;
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gpnum = rsp->gpnum;
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if (rsp->completed == rsp->gpnum)
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gpage = 0;
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else
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gpage = jiffies - rsp->gp_start;
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gpmax = rsp->gp_max;
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raw_spin_unlock_irqrestore(&rnp->lock, flags);
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seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n",
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rsp->name, completed, gpnum, gpage, gpmax);
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}
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static int show_rcugp(struct seq_file *m, void *unused)
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{
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#ifdef CONFIG_TREE_PREEMPT_RCU
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show_one_rcugp(m, &rcu_preempt_state);
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#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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show_one_rcugp(m, &rcu_sched_state);
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show_one_rcugp(m, &rcu_bh_state);
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return 0;
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}
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static int rcugp_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcugp, NULL);
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}
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static const struct file_operations rcugp_fops = {
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.owner = THIS_MODULE,
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.open = rcugp_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
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{
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seq_printf(m, "%3d%cnp=%ld "
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"qsp=%ld rpq=%ld cbr=%ld cng=%ld "
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"gpc=%ld gps=%ld nf=%ld nn=%ld\n",
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rdp->cpu,
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cpu_is_offline(rdp->cpu) ? '!' : ' ',
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rdp->n_rcu_pending,
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rdp->n_rp_qs_pending,
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rdp->n_rp_report_qs,
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rdp->n_rp_cb_ready,
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rdp->n_rp_cpu_needs_gp,
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rdp->n_rp_gp_completed,
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rdp->n_rp_gp_started,
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rdp->n_rp_need_fqs,
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rdp->n_rp_need_nothing);
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}
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static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
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{
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int cpu;
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struct rcu_data *rdp;
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for_each_possible_cpu(cpu) {
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rdp = per_cpu_ptr(rsp->rda, cpu);
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if (rdp->beenonline)
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print_one_rcu_pending(m, rdp);
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}
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}
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static int show_rcu_pending(struct seq_file *m, void *unused)
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{
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#ifdef CONFIG_TREE_PREEMPT_RCU
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seq_puts(m, "rcu_preempt:\n");
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print_rcu_pendings(m, &rcu_preempt_state);
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#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
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seq_puts(m, "rcu_sched:\n");
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print_rcu_pendings(m, &rcu_sched_state);
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seq_puts(m, "rcu_bh:\n");
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print_rcu_pendings(m, &rcu_bh_state);
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return 0;
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}
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static int rcu_pending_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcu_pending, NULL);
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}
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static const struct file_operations rcu_pending_fops = {
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.owner = THIS_MODULE,
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.open = rcu_pending_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int show_rcutorture(struct seq_file *m, void *unused)
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{
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seq_printf(m, "rcutorture test sequence: %lu %s\n",
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rcutorture_testseq >> 1,
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(rcutorture_testseq & 0x1) ? "(test in progress)" : "");
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seq_printf(m, "rcutorture update version number: %lu\n",
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rcutorture_vernum);
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return 0;
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}
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static int rcutorture_open(struct inode *inode, struct file *file)
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{
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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");
|