503 lines
13 KiB
C
503 lines
13 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, you can access it online at
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* http://www.gnu.org/licenses/gpl-2.0.html.
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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 <linux/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 "tree.h"
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DECLARE_PER_CPU_SHARED_ALIGNED(unsigned long, rcu_qs_ctr);
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static int r_open(struct inode *inode, struct file *file,
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const struct seq_operations *op)
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{
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int ret = seq_open(file, op);
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if (!ret) {
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struct seq_file *m = (struct seq_file *)file->private_data;
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m->private = inode->i_private;
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}
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return ret;
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}
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static void *r_start(struct seq_file *m, loff_t *pos)
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{
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struct rcu_state *rsp = (struct rcu_state *)m->private;
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*pos = cpumask_next(*pos - 1, cpu_possible_mask);
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if ((*pos) < nr_cpu_ids)
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return per_cpu_ptr(rsp->rda, *pos);
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return NULL;
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}
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static void *r_next(struct seq_file *m, void *v, loff_t *pos)
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{
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(*pos)++;
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return r_start(m, pos);
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}
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static void r_stop(struct seq_file *m, void *v)
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{
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}
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static int show_rcubarrier(struct seq_file *m, void *v)
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{
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struct rcu_state *rsp = (struct rcu_state *)m->private;
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seq_printf(m, "bcc: %d bseq: %lu\n",
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atomic_read(&rsp->barrier_cpu_count),
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rsp->barrier_sequence);
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return 0;
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}
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static int rcubarrier_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcubarrier, inode->i_private);
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}
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static const struct file_operations rcubarrier_fops = {
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.owner = THIS_MODULE,
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.open = rcubarrier_open,
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.read = seq_read,
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.llseek = no_llseek,
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.release = single_release,
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};
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#ifdef CONFIG_RCU_BOOST
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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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#endif /* #ifdef CONFIG_RCU_BOOST */
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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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long ql, qll;
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if (!rdp->beenonline)
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return;
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seq_printf(m, "%3d%cc=%ld g=%ld cnq=%d/%d:%d",
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rdp->cpu,
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cpu_is_offline(rdp->cpu) ? '!' : ' ',
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ulong2long(rdp->completed), ulong2long(rdp->gpnum),
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rdp->cpu_no_qs.b.norm,
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rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu),
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rdp->core_needs_qs);
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seq_printf(m, " dt=%d/%llx/%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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seq_printf(m, " of=%lu", rdp->offline_fqs);
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rcu_nocb_q_lengths(rdp, &ql, &qll);
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qll += rdp->qlen_lazy;
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ql += rdp->qlen;
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seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",
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qll, ql,
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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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#ifdef CONFIG_RCU_BOOST
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seq_printf(m, " kt=%d/%c ktl=%x",
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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_loops, rdp->cpu) & 0xffff);
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#endif /* #ifdef CONFIG_RCU_BOOST */
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seq_printf(m, " b=%ld", rdp->blimit);
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seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu\n",
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rdp->n_cbs_invoked, rdp->n_nocbs_invoked,
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rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
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}
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static int show_rcudata(struct seq_file *m, void *v)
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{
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print_one_rcu_data(m, (struct rcu_data *)v);
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return 0;
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}
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static const struct seq_operations rcudate_op = {
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.start = r_start,
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.next = r_next,
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.stop = r_stop,
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.show = show_rcudata,
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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 r_open(inode, file, &rcudate_op);
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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 = no_llseek,
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.release = seq_release,
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};
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static int show_rcuexp(struct seq_file *m, void *v)
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{
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struct rcu_state *rsp = (struct rcu_state *)m->private;
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seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n",
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rsp->expedited_sequence,
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atomic_long_read(&rsp->expedited_workdone0),
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atomic_long_read(&rsp->expedited_workdone1),
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atomic_long_read(&rsp->expedited_workdone2),
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atomic_long_read(&rsp->expedited_workdone3),
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atomic_long_read(&rsp->expedited_normal),
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atomic_read(&rsp->expedited_need_qs),
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rsp->expedited_sequence / 2);
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return 0;
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}
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static int rcuexp_open(struct inode *inode, struct file *file)
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{
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return single_open(file, show_rcuexp, inode->i_private);
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}
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static const struct file_operations rcuexp_fops = {
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.owner = THIS_MODULE,
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.open = rcuexp_open,
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.read = seq_read,
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.llseek = no_llseek,
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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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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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seq_printf(m, "j=%04x bt=%04x\n",
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(int)(jiffies & 0xffff),
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(int)(rnp->boost_time & 0xffff));
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seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
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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 = no_llseek,
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.release = single_release,
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};
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#endif /* #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=%ld g=%ld s=%d jfq=%ld j=%x ",
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ulong2long(rsp->completed), ulong2long(gpnum),
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rsp->gp_state,
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(long)(rsp->jiffies_force_qs - jiffies),
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(int)(jiffies & 0xffff));
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seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
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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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READ_ONCE(rsp->n_force_qs_lh), rsp->qlen_lazy, rsp->qlen);
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for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_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->%lx %c%c>%c %d:%d ^%d ",
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rnp->qsmask, rnp->qsmaskinit, rnp->qsmaskinitnext,
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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 *v)
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{
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struct rcu_state *rsp = (struct rcu_state *)m->private;
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print_one_rcu_state(m, rsp);
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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, inode->i_private);
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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 = no_llseek,
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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 = READ_ONCE(rsp->completed);
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gpnum = READ_ONCE(rsp->gpnum);
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if (completed == 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, "completed=%ld gpnum=%ld age=%ld max=%ld\n",
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ulong2long(completed), ulong2long(gpnum), gpage, gpmax);
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}
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static int show_rcugp(struct seq_file *m, void *v)
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{
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struct rcu_state *rsp = (struct rcu_state *)m->private;
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show_one_rcugp(m, rsp);
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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, inode->i_private);
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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 = no_llseek,
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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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if (!rdp->beenonline)
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return;
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seq_printf(m, "%3d%cnp=%ld ",
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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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seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",
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rdp->n_rp_core_needs_qs,
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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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seq_printf(m, "gpc=%ld gps=%ld nn=%ld ndw%ld\n",
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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_nocb_defer_wakeup,
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rdp->n_rp_need_nothing);
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}
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static int show_rcu_pending(struct seq_file *m, void *v)
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{
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print_one_rcu_pending(m, (struct rcu_data *)v);
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return 0;
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}
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static const struct seq_operations rcu_pending_op = {
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.start = r_start,
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.next = r_next,
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.stop = r_stop,
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.show = show_rcu_pending,
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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 r_open(inode, file, &rcu_pending_op);
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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 = no_llseek,
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.release = seq_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);
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}
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static const struct file_operations rcutorture_fops = {
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.owner = THIS_MODULE,
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.open = rcutorture_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 struct dentry *rcudir;
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static int __init rcutree_trace_init(void)
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{
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struct rcu_state *rsp;
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struct dentry *retval;
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struct dentry *rspdir;
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rcudir = debugfs_create_dir("rcu", NULL);
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if (!rcudir)
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goto free_out;
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for_each_rcu_flavor(rsp) {
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rspdir = debugfs_create_dir(rsp->name, rcudir);
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if (!rspdir)
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goto free_out;
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retval = debugfs_create_file("rcudata", 0444,
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rspdir, rsp, &rcudata_fops);
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if (!retval)
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goto free_out;
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retval = debugfs_create_file("rcuexp", 0444,
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rspdir, rsp, &rcuexp_fops);
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if (!retval)
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goto free_out;
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retval = debugfs_create_file("rcu_pending", 0444,
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rspdir, rsp, &rcu_pending_fops);
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if (!retval)
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goto free_out;
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retval = debugfs_create_file("rcubarrier", 0444,
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rspdir, rsp, &rcubarrier_fops);
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if (!retval)
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goto free_out;
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#ifdef CONFIG_RCU_BOOST
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if (rsp == &rcu_preempt_state) {
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retval = debugfs_create_file("rcuboost", 0444,
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rspdir, NULL, &rcu_node_boost_fops);
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if (!retval)
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goto free_out;
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}
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#endif
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retval = debugfs_create_file("rcugp", 0444,
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rspdir, rsp, &rcugp_fops);
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if (!retval)
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|
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;
|
|
}
|
|
|
|
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");
|