x86: fix nmi_watchdog=2 on Pentium-D CPUs
[sfrench/cifs-2.6.git] / kernel / lockdep_proc.c
index 58f35e586ee3b508e693e3cd010a69982ae76b5f..8a135bd163c2cc719b4635b1e511aa87039d6f46 100644 (file)
@@ -5,7 +5,8 @@
  *
  * Started by Ingo Molnar:
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  * Code for /proc/lockdep and /proc/lockdep_stats:
  *
 #include <linux/seq_file.h>
 #include <linux/kallsyms.h>
 #include <linux/debug_locks.h>
+#include <linux/vmalloc.h>
+#include <linux/sort.h>
+#include <asm/uaccess.h>
+#include <asm/div64.h>
 
 #include "lockdep_internals.h"
 
 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct lock_class *class = v;
+       struct lock_class *class;
 
        (*pos)++;
 
-       if (class->lock_entry.next != &all_lock_classes)
-               class = list_entry(class->lock_entry.next, struct lock_class,
-                                 lock_entry);
-       else
-               class = NULL;
-       m->private = class;
+       if (v == SEQ_START_TOKEN)
+               class = m->private;
+       else {
+               class = v;
+
+               if (class->lock_entry.next != &all_lock_classes)
+                       class = list_entry(class->lock_entry.next,
+                                          struct lock_class, lock_entry);
+               else
+                       class = NULL;
+       }
 
        return class;
 }
 
 static void *l_start(struct seq_file *m, loff_t *pos)
 {
-       struct lock_class *class = m->private;
+       struct lock_class *class;
+       loff_t i = 0;
 
-       if (&class->lock_entry == all_lock_classes.next)
-               seq_printf(m, "all lock classes:\n");
+       if (*pos == 0)
+               return SEQ_START_TOKEN;
 
-       return class;
+       list_for_each_entry(class, &all_lock_classes, lock_entry) {
+               if (++i == *pos)
+               return class;
+       }
+       return NULL;
 }
 
 static void l_stop(struct seq_file *m, void *v)
@@ -96,10 +111,15 @@ static void print_name(struct seq_file *m, struct lock_class *class)
 static int l_show(struct seq_file *m, void *v)
 {
        unsigned long nr_forward_deps, nr_backward_deps;
-       struct lock_class *class = m->private;
+       struct lock_class *class = v;
        struct lock_list *entry;
        char c1, c2, c3, c4;
 
+       if (v == SEQ_START_TOKEN) {
+               seq_printf(m, "all lock classes:\n");
+               return 0;
+       }
+
        seq_printf(m, "%p", class->key);
 #ifdef CONFIG_DEBUG_LOCKDEP
        seq_printf(m, " OPS:%8ld", class->ops);
@@ -271,8 +291,10 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
        if (nr_list_entries)
                factor = sum_forward_deps / nr_list_entries;
 
+#ifdef CONFIG_PROVE_LOCKING
        seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
                        nr_lock_chains, MAX_LOCKDEP_CHAINS);
+#endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS
        seq_printf(m, " in-hardirq chains:             %11u\n",
@@ -339,9 +361,303 @@ static const struct file_operations proc_lockdep_stats_operations = {
        .open           = lockdep_stats_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
-       .release        = seq_release,
+       .release        = single_release,
 };
 
+#ifdef CONFIG_LOCK_STAT
+
+struct lock_stat_data {
+       struct lock_class *class;
+       struct lock_class_stats stats;
+};
+
+struct lock_stat_seq {
+       struct lock_stat_data *iter;
+       struct lock_stat_data *iter_end;
+       struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
+};
+
+/*
+ * sort on absolute number of contentions
+ */
+static int lock_stat_cmp(const void *l, const void *r)
+{
+       const struct lock_stat_data *dl = l, *dr = r;
+       unsigned long nl, nr;
+
+       nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
+       nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
+
+       return nr - nl;
+}
+
+static void seq_line(struct seq_file *m, char c, int offset, int length)
+{
+       int i;
+
+       for (i = 0; i < offset; i++)
+               seq_puts(m, " ");
+       for (i = 0; i < length; i++)
+               seq_printf(m, "%c", c);
+       seq_puts(m, "\n");
+}
+
+static void snprint_time(char *buf, size_t bufsiz, s64 nr)
+{
+       unsigned long rem;
+
+       rem = do_div(nr, 1000); /* XXX: do_div_signed */
+       snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10);
+}
+
+static void seq_time(struct seq_file *m, s64 time)
+{
+       char num[15];
+
+       snprint_time(num, sizeof(num), time);
+       seq_printf(m, " %14s", num);
+}
+
+static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
+{
+       seq_printf(m, "%14lu", lt->nr);
+       seq_time(m, lt->min);
+       seq_time(m, lt->max);
+       seq_time(m, lt->total);
+}
+
+static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
+{
+       char name[39];
+       struct lock_class *class;
+       struct lock_class_stats *stats;
+       int i, namelen;
+
+       class = data->class;
+       stats = &data->stats;
+
+       namelen = 38;
+       if (class->name_version > 1)
+               namelen -= 2; /* XXX truncates versions > 9 */
+       if (class->subclass)
+               namelen -= 2;
+
+       if (!class->name) {
+               char str[KSYM_NAME_LEN];
+               const char *key_name;
+
+               key_name = __get_key_name(class->key, str);
+               snprintf(name, namelen, "%s", key_name);
+       } else {
+               snprintf(name, namelen, "%s", class->name);
+       }
+       namelen = strlen(name);
+       if (class->name_version > 1) {
+               snprintf(name+namelen, 3, "#%d", class->name_version);
+               namelen += 2;
+       }
+       if (class->subclass) {
+               snprintf(name+namelen, 3, "/%d", class->subclass);
+               namelen += 2;
+       }
+
+       if (stats->write_holdtime.nr) {
+               if (stats->read_holdtime.nr)
+                       seq_printf(m, "%38s-W:", name);
+               else
+                       seq_printf(m, "%40s:", name);
+
+               seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
+               seq_lock_time(m, &stats->write_waittime);
+               seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
+               seq_lock_time(m, &stats->write_holdtime);
+               seq_puts(m, "\n");
+       }
+
+       if (stats->read_holdtime.nr) {
+               seq_printf(m, "%38s-R:", name);
+               seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
+               seq_lock_time(m, &stats->read_waittime);
+               seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
+               seq_lock_time(m, &stats->read_holdtime);
+               seq_puts(m, "\n");
+       }
+
+       if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
+               return;
+
+       if (stats->read_holdtime.nr)
+               namelen += 2;
+
+       for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
+               char sym[KSYM_SYMBOL_LEN];
+               char ip[32];
+
+               if (class->contention_point[i] == 0)
+                       break;
+
+               if (!i)
+                       seq_line(m, '-', 40-namelen, namelen);
+
+               sprint_symbol(sym, class->contention_point[i]);
+               snprintf(ip, sizeof(ip), "[<%p>]",
+                               (void *)class->contention_point[i]);
+               seq_printf(m, "%40s %14lu %29s %s\n", name,
+                               stats->contention_point[i],
+                               ip, sym);
+       }
+       if (i) {
+               seq_puts(m, "\n");
+               seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
+               seq_puts(m, "\n");
+       }
+}
+
+static void seq_header(struct seq_file *m)
+{
+       seq_printf(m, "lock_stat version 0.2\n");
+       seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
+       seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
+                       "%14s %14s\n",
+                       "class name",
+                       "con-bounces",
+                       "contentions",
+                       "waittime-min",
+                       "waittime-max",
+                       "waittime-total",
+                       "acq-bounces",
+                       "acquisitions",
+                       "holdtime-min",
+                       "holdtime-max",
+                       "holdtime-total");
+       seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
+       seq_printf(m, "\n");
+}
+
+static void *ls_start(struct seq_file *m, loff_t *pos)
+{
+       struct lock_stat_seq *data = m->private;
+
+       if (*pos == 0)
+               return SEQ_START_TOKEN;
+
+       data->iter = data->stats + *pos;
+       if (data->iter >= data->iter_end)
+               data->iter = NULL;
+
+       return data->iter;
+}
+
+static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
+{
+       struct lock_stat_seq *data = m->private;
+
+       (*pos)++;
+
+       if (v == SEQ_START_TOKEN)
+               data->iter = data->stats;
+       else {
+               data->iter = v;
+               data->iter++;
+       }
+
+       if (data->iter == data->iter_end)
+               data->iter = NULL;
+
+       return data->iter;
+}
+
+static void ls_stop(struct seq_file *m, void *v)
+{
+}
+
+static int ls_show(struct seq_file *m, void *v)
+{
+       if (v == SEQ_START_TOKEN)
+               seq_header(m);
+       else
+               seq_stats(m, v);
+
+       return 0;
+}
+
+static struct seq_operations lockstat_ops = {
+       .start  = ls_start,
+       .next   = ls_next,
+       .stop   = ls_stop,
+       .show   = ls_show,
+};
+
+static int lock_stat_open(struct inode *inode, struct file *file)
+{
+       int res;
+       struct lock_class *class;
+       struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
+
+       if (!data)
+               return -ENOMEM;
+
+       res = seq_open(file, &lockstat_ops);
+       if (!res) {
+               struct lock_stat_data *iter = data->stats;
+               struct seq_file *m = file->private_data;
+
+               data->iter = iter;
+               list_for_each_entry(class, &all_lock_classes, lock_entry) {
+                       iter->class = class;
+                       iter->stats = lock_stats(class);
+                       iter++;
+               }
+               data->iter_end = iter;
+
+               sort(data->stats, data->iter_end - data->iter,
+                               sizeof(struct lock_stat_data),
+                               lock_stat_cmp, NULL);
+
+               m->private = data;
+       } else
+               vfree(data);
+
+       return res;
+}
+
+static ssize_t lock_stat_write(struct file *file, const char __user *buf,
+                              size_t count, loff_t *ppos)
+{
+       struct lock_class *class;
+       char c;
+
+       if (count) {
+               if (get_user(c, buf))
+                       return -EFAULT;
+
+               if (c != '0')
+                       return count;
+
+               list_for_each_entry(class, &all_lock_classes, lock_entry)
+                       clear_lock_stats(class);
+       }
+       return count;
+}
+
+static int lock_stat_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *seq = file->private_data;
+
+       vfree(seq->private);
+       seq->private = NULL;
+       return seq_release(inode, file);
+}
+
+static const struct file_operations proc_lock_stat_operations = {
+       .open           = lock_stat_open,
+       .write          = lock_stat_write,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = lock_stat_release,
+};
+#endif /* CONFIG_LOCK_STAT */
+
 static int __init lockdep_proc_init(void)
 {
        struct proc_dir_entry *entry;
@@ -354,6 +670,12 @@ static int __init lockdep_proc_init(void)
        if (entry)
                entry->proc_fops = &proc_lockdep_stats_operations;
 
+#ifdef CONFIG_LOCK_STAT
+       entry = create_proc_entry("lock_stat", S_IRUSR, NULL);
+       if (entry)
+               entry->proc_fops = &proc_lock_stat_operations;
+#endif
+
        return 0;
 }