/* * Read-Copy Update tracing for realtime 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, 2006 * * Papers: http://www.rdrop.com/users/paulmck/RCU * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU/ *.txt * */ #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/rcupreempt_trace.h> #include <linux/debugfs.h> static struct mutex rcupreempt_trace_mutex; static char *rcupreempt_trace_buf; #define RCUPREEMPT_TRACE_BUF_SIZE 4096 void rcupreempt_trace_move2done(struct rcupreempt_trace *trace) { trace->done_length += trace->wait_length; trace->done_add += trace->wait_length; trace->wait_length = 0; } void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace) { trace->wait_length += trace->next_length; trace->wait_add += trace->next_length; trace->next_length = 0; } void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace) { atomic_inc(&trace->rcu_try_flip_1); } void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace) { atomic_inc(&trace->rcu_try_flip_e1); } void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_i1++; } void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_ie1++; } void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_g1++; } void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_a1++; } void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_ae1++; } void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace) { trace->rcu_try_flip_a2++; } void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_z1++; } void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_ze1++; } void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace) { trace->rcu_try_flip_z2++; } void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_m1++; } void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace) { trace->rcu_try_flip_me1++; } void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace) { trace->rcu_try_flip_m2++; } void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace) { trace->rcu_check_callbacks++; } void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace) { trace->done_remove += trace->done_length; trace->done_length = 0; } void rcupreempt_trace_invoke(struct rcupreempt_trace *trace) { atomic_inc(&trace->done_invoked); } void rcupreempt_trace_next_add(struct rcupreempt_trace *trace) { trace->next_add++; trace->next_length++; } static void rcupreempt_trace_sum(struct rcupreempt_trace *sp) { struct rcupreempt_trace *cp; int cpu; memset(sp, 0, sizeof(*sp)); for_each_possible_cpu(cpu) { cp = rcupreempt_trace_cpu(cpu); sp->next_length += cp->next_length; sp->next_add += cp->next_add; sp->wait_length += cp->wait_length; sp->wait_add += cp->wait_add; sp->done_length += cp->done_length; sp->done_add += cp->done_add; sp->done_remove += cp->done_remove; atomic_set(&sp->done_invoked, atomic_read(&cp->done_invoked)); sp->rcu_check_callbacks += cp->rcu_check_callbacks; atomic_set(&sp->rcu_try_flip_1, atomic_read(&cp->rcu_try_flip_1)); atomic_set(&sp->rcu_try_flip_e1, atomic_read(&cp->rcu_try_flip_e1)); sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1; sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1; sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1; sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1; sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1; sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2; sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1; sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1; sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2; sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1; sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1; sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2; } } static ssize_t rcustats_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { struct rcupreempt_trace trace; ssize_t bcount; int cnt = 0; rcupreempt_trace_sum(&trace); mutex_lock(&rcupreempt_trace_mutex); snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, "ggp=%ld rcc=%ld\n", rcu_batches_completed(), trace.rcu_check_callbacks); snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", trace.next_add, trace.next_length, trace.wait_add, trace.wait_length, trace.done_add, trace.done_length, trace.done_remove, atomic_read(&trace.done_invoked), atomic_read(&trace.rcu_try_flip_1), atomic_read(&trace.rcu_try_flip_e1), trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, trace.rcu_try_flip_g1, trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, trace.rcu_try_flip_a2, trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, trace.rcu_try_flip_z2, trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, trace.rcu_try_flip_m2); bcount = simple_read_from_buffer(buffer, count, ppos, rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); mutex_unlock(&rcupreempt_trace_mutex); return bcount; } static ssize_t rcugp_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { long oldgp = rcu_batches_completed(); ssize_t bcount; mutex_lock(&rcupreempt_trace_mutex); synchronize_rcu(); snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE, "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed()); bcount = simple_read_from_buffer(buffer, count, ppos, rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); mutex_unlock(&rcupreempt_trace_mutex); return bcount; } static ssize_t rcuctrs_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { int cnt = 0; int cpu; int f = rcu_batches_completed() & 0x1; ssize_t bcount; mutex_lock(&rcupreempt_trace_mutex); cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE, "CPU last cur F M\n"); for_each_online_cpu(cpu) { long *flipctr = rcupreempt_flipctr(cpu); cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, "%3d %4ld %3ld %d %d\n", cpu, flipctr[!f], flipctr[f], rcupreempt_flip_flag(cpu), rcupreempt_mb_flag(cpu)); } cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, "ggp = %ld, state = %s\n", rcu_batches_completed(), rcupreempt_try_flip_state_name()); cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, "\n"); bcount = simple_read_from_buffer(buffer, count, ppos, rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); mutex_unlock(&rcupreempt_trace_mutex); return bcount; } static struct file_operations rcustats_fops = { .owner = THIS_MODULE, .read = rcustats_read, }; static struct file_operations rcugp_fops = { .owner = THIS_MODULE, .read = rcugp_read, }; static struct file_operations rcuctrs_fops = { .owner = THIS_MODULE, .read = rcuctrs_read, }; static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir; static int rcupreempt_debugfs_init(void) { rcudir = debugfs_create_dir("rcu", NULL); if (!rcudir) goto out; statdir = debugfs_create_file("rcustats", 0444, rcudir, NULL, &rcustats_fops); if (!statdir) goto free_out; gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); if (!gpdir) goto free_out; ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir, NULL, &rcuctrs_fops); if (!ctrsdir) goto free_out; return 0; free_out: if (statdir) debugfs_remove(statdir); if (gpdir) debugfs_remove(gpdir); debugfs_remove(rcudir); out: return 1; } static int __init rcupreempt_trace_init(void) { mutex_init(&rcupreempt_trace_mutex); rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); if (!rcupreempt_trace_buf) return 1; return rcupreempt_debugfs_init(); } static void __exit rcupreempt_trace_cleanup(void) { debugfs_remove(statdir); debugfs_remove(gpdir); debugfs_remove(ctrsdir); debugfs_remove(rcudir); kfree(rcupreempt_trace_buf); } module_init(rcupreempt_trace_init); module_exit(rcupreempt_trace_cleanup);