diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/lockdep.c | 44 | ||||
| -rw-r--r-- | kernel/lockdep_proc.c | 266 |
2 files changed, 310 insertions, 0 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 70ca4db28af..a8dc99d9fef 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -149,6 +149,50 @@ static void lock_time_inc(struct lock_time *lt, s64 time) lt->nr++; } +static inline void lock_time_add(struct lock_time *src, struct lock_time *dst) +{ + dst->min += src->min; + dst->max += src->max; + dst->total += src->total; + dst->nr += src->nr; +} + +struct lock_class_stats lock_stats(struct lock_class *class) +{ + struct lock_class_stats stats; + int cpu, i; + + memset(&stats, 0, sizeof(struct lock_class_stats)); + for_each_possible_cpu(cpu) { + struct lock_class_stats *pcs = + &per_cpu(lock_stats, cpu)[class - lock_classes]; + + for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++) + stats.contention_point[i] += pcs->contention_point[i]; + + lock_time_add(&pcs->read_waittime, &stats.read_waittime); + lock_time_add(&pcs->write_waittime, &stats.write_waittime); + + lock_time_add(&pcs->read_holdtime, &stats.read_holdtime); + lock_time_add(&pcs->write_holdtime, &stats.write_holdtime); + } + + return stats; +} + +void clear_lock_stats(struct lock_class *class) +{ + int cpu; + + for_each_possible_cpu(cpu) { + struct lock_class_stats *cpu_stats = + &per_cpu(lock_stats, cpu)[class - lock_classes]; + + memset(cpu_stats, 0, sizeof(struct lock_class_stats)); + } + memset(class->contention_point, 0, sizeof(class->contention_point)); +} + static struct lock_class_stats *get_lock_stats(struct lock_class *class) { return &get_cpu_var(lock_stats)[class - lock_classes]; diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index 2fde34127e2..e682926c9ad 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -15,6 +15,10 @@ #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" @@ -344,6 +348,262 @@ static const struct file_operations proc_lockdep_stats_operations = { .release = seq_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; + + snprintf(name, 38, "%s", class->name); + namelen = strlen(name); + + if (stats->write_holdtime.nr) { + if (stats->read_holdtime.nr) + seq_printf(m, "%38s-W:", name); + else + seq_printf(m, "%40s:", name); + + seq_lock_time(m, &stats->write_waittime); + seq_puts(m, " "); + seq_lock_time(m, &stats->write_holdtime); + seq_puts(m, "\n"); + } + + if (stats->read_holdtime.nr) { + seq_printf(m, "%38s-R:", name); + seq_lock_time(m, &stats->read_waittime); + seq_puts(m, " "); + 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 + 8 * (14 + 1)); + seq_puts(m, "\n"); + } +} + +static void seq_header(struct seq_file *m) +{ + seq_printf(m, "lock_stat version 0.1\n"); + seq_line(m, '-', 0, 40 + 1 + 8 * (14 + 1)); + seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s\n", + "class name", + "contentions", + "waittime-min", + "waittime-max", + "waittime-total", + "acquisitions", + "holdtime-min", + "holdtime-max", + "holdtime-total"); + seq_line(m, '-', 0, 40 + 1 + 8 * (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 (data->iter == data->stats) + seq_header(m); + + return data->iter; +} + +static void *ls_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct lock_stat_seq *data = m->private; + + (*pos)++; + + 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) +{ + struct lock_stat_seq *data = m->private; + + seq_stats(m, data->iter); + 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; @@ -356,6 +616,12 @@ 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; } |