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jbd2: Use tracepoints for history file
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The /proc/fs/jbd2/<dev>/history was maintained manually; by using
tracepoints, we can get all of the existing functionality of the /proc
file plus extra capabilities thanks to the ftrace infrastructure.  We
save memory as a bonus.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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Theodore Ts'o committed Sep 30, 2009
1 parent 296c355 commit bf69932
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Showing 5 changed files with 130 additions and 228 deletions.
7 changes: 7 additions & 0 deletions fs/jbd2/checkpoint.c
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Original file line number Diff line number Diff line change
Expand Up @@ -643,6 +643,7 @@ int __jbd2_journal_clean_checkpoint_list(journal_t *journal)

int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
{
struct transaction_chp_stats_s *stats;
transaction_t *transaction;
journal_t *journal;
int ret = 0;
Expand Down Expand Up @@ -679,6 +680,12 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh)

/* OK, that was the last buffer for the transaction: we can now
safely remove this transaction from the log */
stats = &transaction->t_chp_stats;
if (stats->cs_chp_time)
stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time,
jiffies);
trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev,
transaction->t_tid, stats);

__jbd2_journal_drop_transaction(journal, transaction);
kfree(transaction);
Expand Down
59 changes: 28 additions & 31 deletions fs/jbd2/commit.c
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Original file line number Diff line number Diff line change
Expand Up @@ -410,10 +410,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
if (commit_transaction->t_synchronous_commit)
write_op = WRITE_SYNC_PLUG;
trace_jbd2_commit_locking(journal, commit_transaction);
stats.u.run.rs_wait = commit_transaction->t_max_wait;
stats.u.run.rs_locked = jiffies;
stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
stats.u.run.rs_locked);
stats.run.rs_wait = commit_transaction->t_max_wait;
stats.run.rs_locked = jiffies;
stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
stats.run.rs_locked);

spin_lock(&commit_transaction->t_handle_lock);
while (commit_transaction->t_updates) {
Expand Down Expand Up @@ -486,9 +486,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
jbd2_journal_switch_revoke_table(journal);

trace_jbd2_commit_flushing(journal, commit_transaction);
stats.u.run.rs_flushing = jiffies;
stats.u.run.rs_locked = jbd2_time_diff(stats.u.run.rs_locked,
stats.u.run.rs_flushing);
stats.run.rs_flushing = jiffies;
stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
stats.run.rs_flushing);

commit_transaction->t_state = T_FLUSH;
journal->j_committing_transaction = commit_transaction;
Expand Down Expand Up @@ -523,11 +523,11 @@ void jbd2_journal_commit_transaction(journal_t *journal)
spin_unlock(&journal->j_state_lock);

trace_jbd2_commit_logging(journal, commit_transaction);
stats.u.run.rs_logging = jiffies;
stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing,
stats.u.run.rs_logging);
stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
stats.u.run.rs_blocks_logged = 0;
stats.run.rs_logging = jiffies;
stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
stats.run.rs_logging);
stats.run.rs_blocks = commit_transaction->t_outstanding_credits;
stats.run.rs_blocks_logged = 0;

J_ASSERT(commit_transaction->t_nr_buffers <=
commit_transaction->t_outstanding_credits);
Expand Down Expand Up @@ -695,7 +695,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
submit_bh(write_op, bh);
}
cond_resched();
stats.u.run.rs_blocks_logged += bufs;
stats.run.rs_blocks_logged += bufs;

/* Force a new descriptor to be generated next
time round the loop. */
Expand Down Expand Up @@ -988,33 +988,30 @@ void jbd2_journal_commit_transaction(journal_t *journal)
J_ASSERT(commit_transaction->t_state == T_COMMIT);

commit_transaction->t_start = jiffies;
stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging,
commit_transaction->t_start);
stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
commit_transaction->t_start);

/*
* File the transaction for history
* File the transaction statistics
*/
stats.ts_type = JBD2_STATS_RUN;
stats.ts_tid = commit_transaction->t_tid;
stats.u.run.rs_handle_count = commit_transaction->t_handle_count;
spin_lock(&journal->j_history_lock);
memcpy(journal->j_history + journal->j_history_cur, &stats,
sizeof(stats));
if (++journal->j_history_cur == journal->j_history_max)
journal->j_history_cur = 0;
stats.run.rs_handle_count = commit_transaction->t_handle_count;
trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
commit_transaction->t_tid, &stats.run);

/*
* Calculate overall stats
*/
spin_lock(&journal->j_history_lock);
journal->j_stats.ts_tid++;
journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait;
journal->j_stats.u.run.rs_running += stats.u.run.rs_running;
journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked;
journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing;
journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging;
journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count;
journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks;
journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged;
journal->j_stats.run.rs_wait += stats.run.rs_wait;
journal->j_stats.run.rs_running += stats.run.rs_running;
journal->j_stats.run.rs_locked += stats.run.rs_locked;
journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
journal->j_stats.run.rs_logging += stats.run.rs_logging;
journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
spin_unlock(&journal->j_history_lock);

commit_transaction->t_state = T_FINISHED;
Expand Down
187 changes: 10 additions & 177 deletions fs/jbd2/journal.c
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Original file line number Diff line number Diff line change
Expand Up @@ -676,153 +676,6 @@ struct jbd2_stats_proc_session {
int max;
};

static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s,
struct transaction_stats_s *ts,
int first)
{
if (ts == s->stats + s->max)
ts = s->stats;
if (!first && ts == s->stats + s->start)
return NULL;
while (ts->ts_type == 0) {
ts++;
if (ts == s->stats + s->max)
ts = s->stats;
if (ts == s->stats + s->start)
return NULL;
}
return ts;

}

static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos)
{
struct jbd2_stats_proc_session *s = seq->private;
struct transaction_stats_s *ts;
int l = *pos;

if (l == 0)
return SEQ_START_TOKEN;
ts = jbd2_history_skip_empty(s, s->stats + s->start, 1);
if (!ts)
return NULL;
l--;
while (l) {
ts = jbd2_history_skip_empty(s, ++ts, 0);
if (!ts)
break;
l--;
}
return ts;
}

static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct jbd2_stats_proc_session *s = seq->private;
struct transaction_stats_s *ts = v;

++*pos;
if (v == SEQ_START_TOKEN)
return jbd2_history_skip_empty(s, s->stats + s->start, 1);
else
return jbd2_history_skip_empty(s, ++ts, 0);
}

static int jbd2_seq_history_show(struct seq_file *seq, void *v)
{
struct transaction_stats_s *ts = v;
if (v == SEQ_START_TOKEN) {
seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s "
"%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid",
"wait", "run", "lock", "flush", "log", "hndls",
"block", "inlog", "ctime", "write", "drop",
"close");
return 0;
}
if (ts->ts_type == JBD2_STATS_RUN)
seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u "
"%-6lu %-5lu %-5lu\n", "R", ts->ts_tid,
jiffies_to_msecs(ts->u.run.rs_wait),
jiffies_to_msecs(ts->u.run.rs_running),
jiffies_to_msecs(ts->u.run.rs_locked),
jiffies_to_msecs(ts->u.run.rs_flushing),
jiffies_to_msecs(ts->u.run.rs_logging),
ts->u.run.rs_handle_count,
ts->u.run.rs_blocks,
ts->u.run.rs_blocks_logged);
else if (ts->ts_type == JBD2_STATS_CHECKPOINT)
seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n",
"C", ts->ts_tid, " ",
jiffies_to_msecs(ts->u.chp.cs_chp_time),
ts->u.chp.cs_written, ts->u.chp.cs_dropped,
ts->u.chp.cs_forced_to_close);
else
J_ASSERT(0);
return 0;
}

static void jbd2_seq_history_stop(struct seq_file *seq, void *v)
{
}

static const struct seq_operations jbd2_seq_history_ops = {
.start = jbd2_seq_history_start,
.next = jbd2_seq_history_next,
.stop = jbd2_seq_history_stop,
.show = jbd2_seq_history_show,
};

static int jbd2_seq_history_open(struct inode *inode, struct file *file)
{
journal_t *journal = PDE(inode)->data;
struct jbd2_stats_proc_session *s;
int rc, size;

s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s == NULL)
return -ENOMEM;
size = sizeof(struct transaction_stats_s) * journal->j_history_max;
s->stats = kmalloc(size, GFP_KERNEL);
if (s->stats == NULL) {
kfree(s);
return -ENOMEM;
}
spin_lock(&journal->j_history_lock);
memcpy(s->stats, journal->j_history, size);
s->max = journal->j_history_max;
s->start = journal->j_history_cur % s->max;
spin_unlock(&journal->j_history_lock);

rc = seq_open(file, &jbd2_seq_history_ops);
if (rc == 0) {
struct seq_file *m = file->private_data;
m->private = s;
} else {
kfree(s->stats);
kfree(s);
}
return rc;

}

static int jbd2_seq_history_release(struct inode *inode, struct file *file)
{
struct seq_file *seq = file->private_data;
struct jbd2_stats_proc_session *s = seq->private;

kfree(s->stats);
kfree(s);
return seq_release(inode, file);
}

static struct file_operations jbd2_seq_history_fops = {
.owner = THIS_MODULE,
.open = jbd2_seq_history_open,
.read = seq_read,
.llseek = seq_lseek,
.release = jbd2_seq_history_release,
};

static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
{
return *pos ? NULL : SEQ_START_TOKEN;
Expand All @@ -839,29 +692,29 @@ static int jbd2_seq_info_show(struct seq_file *seq, void *v)

if (v != SEQ_START_TOKEN)
return 0;
seq_printf(seq, "%lu transaction, each upto %u blocks\n",
seq_printf(seq, "%lu transaction, each up to %u blocks\n",
s->stats->ts_tid,
s->journal->j_max_transaction_buffers);
if (s->stats->ts_tid == 0)
return 0;
seq_printf(seq, "average: \n %ums waiting for transaction\n",
jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid));
jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
seq_printf(seq, " %ums running transaction\n",
jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid));
jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
seq_printf(seq, " %ums transaction was being locked\n",
jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid));
jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
seq_printf(seq, " %ums flushing data (in ordered mode)\n",
jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid));
jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
seq_printf(seq, " %ums logging transaction\n",
jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid));
jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
seq_printf(seq, " %lluus average transaction commit time\n",
div_u64(s->journal->j_average_commit_time, 1000));
seq_printf(seq, " %lu handles per transaction\n",
s->stats->u.run.rs_handle_count / s->stats->ts_tid);
s->stats->run.rs_handle_count / s->stats->ts_tid);
seq_printf(seq, " %lu blocks per transaction\n",
s->stats->u.run.rs_blocks / s->stats->ts_tid);
s->stats->run.rs_blocks / s->stats->ts_tid);
seq_printf(seq, " %lu logged blocks per transaction\n",
s->stats->u.run.rs_blocks_logged / s->stats->ts_tid);
s->stats->run.rs_blocks_logged / s->stats->ts_tid);
return 0;
}

Expand Down Expand Up @@ -931,8 +784,6 @@ static void jbd2_stats_proc_init(journal_t *journal)
{
journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
if (journal->j_proc_entry) {
proc_create_data("history", S_IRUGO, journal->j_proc_entry,
&jbd2_seq_history_fops, journal);
proc_create_data("info", S_IRUGO, journal->j_proc_entry,
&jbd2_seq_info_fops, journal);
}
Expand All @@ -941,27 +792,9 @@ static void jbd2_stats_proc_init(journal_t *journal)
static void jbd2_stats_proc_exit(journal_t *journal)
{
remove_proc_entry("info", journal->j_proc_entry);
remove_proc_entry("history", journal->j_proc_entry);
remove_proc_entry(journal->j_devname, proc_jbd2_stats);
}

static void journal_init_stats(journal_t *journal)
{
int size;

if (!proc_jbd2_stats)
return;

journal->j_history_max = 100;
size = sizeof(struct transaction_stats_s) * journal->j_history_max;
journal->j_history = kzalloc(size, GFP_KERNEL);
if (!journal->j_history) {
journal->j_history_max = 0;
return;
}
spin_lock_init(&journal->j_history_lock);
}

/*
* Management for journal control blocks: functions to create and
* destroy journal_t structures, and to initialise and read existing
Expand Down Expand Up @@ -1006,7 +839,7 @@ static journal_t * journal_init_common (void)
goto fail;
}

journal_init_stats(journal);
spin_lock_init(&journal->j_history_lock);

return journal;
fail:
Expand Down
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