#include <linux/time.h>
#include <asm/uaccess.h>
-static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
static unsigned int blktrace_seq __read_mostly = 1;
/*
const int cpu = smp_processor_id();
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
- t->time = cpu_clock(cpu) - per_cpu(blk_trace_cpu_offset, cpu);
+ t->time = ktime_to_ns(ktime_get());
t->device = bt->dev;
t->action = action;
t->pid = pid;
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->sequence = ++(*sequence);
- t->time = cpu_clock(cpu) - per_cpu(blk_trace_cpu_offset, cpu);
+ t->time = ktime_to_ns(ktime_get());
t->sector = sector;
t->bytes = bytes;
t->action = what;
EXPORT_SYMBOL_GPL(__blk_add_trace);
static struct dentry *blk_tree_root;
-static struct mutex blk_tree_mutex;
+static DEFINE_MUTEX(blk_tree_mutex);
static unsigned int root_users;
static inline void blk_remove_root(void)
static struct dentry *blk_create_tree(const char *blk_name)
{
struct dentry *dir = NULL;
+ int created = 0;
mutex_lock(&blk_tree_mutex);
blk_tree_root = debugfs_create_dir("block", NULL);
if (!blk_tree_root)
goto err;
+ created = 1;
}
dir = debugfs_create_dir(blk_name, blk_tree_root);
if (dir)
root_users++;
- else
- blk_remove_root();
+ else {
+ /* Delete root only if we created it */
+ if (created)
+ blk_remove_root();
+ }
err:
mutex_unlock(&blk_tree_mutex);
kfree(bt);
}
-static int blk_trace_remove(struct request_queue *q)
+int blk_trace_remove(struct request_queue *q)
{
struct blk_trace *bt;
return 0;
}
+EXPORT_SYMBOL_GPL(blk_trace_remove);
static int blk_dropped_open(struct inode *inode, struct file *filp)
{
/*
* Setup everything required to start tracing
*/
-int do_blk_trace_setup(struct request_queue *q, struct block_device *bdev,
+int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct blk_user_trace_setup *buts)
{
struct blk_trace *old_bt, *bt = NULL;
struct dentry *dir = NULL;
- char b[BDEVNAME_SIZE];
int ret, i;
if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
- strcpy(buts->name, bdevname(bdev, b));
+ strcpy(buts->name, name);
/*
* some device names have larger paths - convert the slashes
goto err;
bt->dir = dir;
- bt->dev = bdev->bd_dev;
+ bt->dev = dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
return ret;
}
-static int blk_trace_setup(struct request_queue *q, struct block_device *bdev,
- char __user *arg)
+int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+ char __user *arg)
{
struct blk_user_trace_setup buts;
int ret;
if (ret)
return -EFAULT;
- ret = do_blk_trace_setup(q, bdev, &buts);
+ ret = do_blk_trace_setup(q, name, dev, &buts);
if (ret)
return ret;
return 0;
}
+EXPORT_SYMBOL_GPL(blk_trace_setup);
-static int blk_trace_startstop(struct request_queue *q, int start)
+int blk_trace_startstop(struct request_queue *q, int start)
{
struct blk_trace *bt;
int ret;
return ret;
}
+EXPORT_SYMBOL_GPL(blk_trace_startstop);
/**
* blk_trace_ioctl: - handle the ioctls associated with tracing
{
struct request_queue *q;
int ret, start = 0;
+ char b[BDEVNAME_SIZE];
q = bdev_get_queue(bdev);
if (!q)
switch (cmd) {
case BLKTRACESETUP:
- ret = blk_trace_setup(q, bdev, arg);
+ strcpy(b, bdevname(bdev, b));
+ ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
break;
case BLKTRACESTART:
start = 1;
blk_trace_remove(q);
}
}
-
-/*
- * Average offset over two calls to cpu_clock() with a gettimeofday()
- * in the middle
- */
-static void blk_check_time(unsigned long long *t, int this_cpu)
-{
- unsigned long long a, b;
- struct timeval tv;
-
- a = cpu_clock(this_cpu);
- do_gettimeofday(&tv);
- b = cpu_clock(this_cpu);
-
- *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
- *t -= (a + b) / 2;
-}
-
-/*
- * calibrate our inter-CPU timings
- */
-static void blk_trace_check_cpu_time(void *data)
-{
- unsigned long long *t;
- int this_cpu = get_cpu();
-
- t = &per_cpu(blk_trace_cpu_offset, this_cpu);
-
- /*
- * Just call it twice, hopefully the second call will be cache hot
- * and a little more precise
- */
- blk_check_time(t, this_cpu);
- blk_check_time(t, this_cpu);
-
- put_cpu();
-}
-
-static void blk_trace_set_ht_offsets(void)
-{
-#if defined(CONFIG_SCHED_SMT)
- int cpu, i;
-
- /*
- * now make sure HT siblings have the same time offset
- */
- preempt_disable();
- for_each_online_cpu(cpu) {
- unsigned long long *cpu_off, *sibling_off;
-
- for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu)) {
- if (i == cpu)
- continue;
-
- cpu_off = &per_cpu(blk_trace_cpu_offset, cpu);
- sibling_off = &per_cpu(blk_trace_cpu_offset, i);
- *sibling_off = *cpu_off;
- }
- }
- preempt_enable();
-#endif
-}
-
-static __init int blk_trace_init(void)
-{
- mutex_init(&blk_tree_mutex);
- on_each_cpu(blk_trace_check_cpu_time, NULL, 1, 1);
- blk_trace_set_ht_offsets();
-
- return 0;
-}
-
-module_init(blk_trace_init);
-