diff options
| author | Theodore Ts'o | 2013-02-06 22:30:23 -0500 |
|---|---|---|
| committer | Theodore Ts'o | 2013-02-06 22:30:23 -0500 |
| commit | 9fff24aa2c5c504aadead1ff9599e813604c2e53 (patch) | |
| tree | 24bbb1691ec816aed648a895882526ce361ec92f /fs | |
| parent | 40ae3487628235e5f1eb27542cca0cdb6e5dbe16 (diff) | |
jbd2: track request delay statistics
Track the delay between when we first request that the commit begin
and when it actually begins, so we can see how much of a gap exists.
In theory, this should just be the remaining scheduling quantuum of
the thread which requested the commit (assuming it was not a
synchronous operation which triggered the commit request) plus
scheduling overhead; however, it's possible that real time processes
might get in the way of letting the kjournald thread from executing.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/jbd2/commit.c | 8 | ||||
| -rw-r--r-- | fs/jbd2/journal.c | 12 | ||||
| -rw-r--r-- | fs/jbd2/transaction.c | 1 |
3 files changed, 18 insertions, 3 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 3091d42992f0..750c70148eff 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -435,7 +435,12 @@ void jbd2_journal_commit_transaction(journal_t *journal) trace_jbd2_commit_locking(journal, commit_transaction); stats.run.rs_wait = commit_transaction->t_max_wait; + stats.run.rs_request_delay = 0; stats.run.rs_locked = jiffies; + if (commit_transaction->t_requested) + stats.run.rs_request_delay = + jbd2_time_diff(commit_transaction->t_requested, + stats.run.rs_locked); stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start, stats.run.rs_locked); @@ -1116,7 +1121,10 @@ restart_loop: */ spin_lock(&journal->j_history_lock); journal->j_stats.ts_tid++; + if (commit_transaction->t_requested) + journal->j_stats.ts_requested++; journal->j_stats.run.rs_wait += stats.run.rs_wait; + journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay; 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; diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 1a80e3146a59..4ba2e81e35ac 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -533,6 +533,7 @@ int __jbd2_log_start_commit(journal_t *journal, tid_t target) jbd_debug(1, "JBD2: requesting commit %d/%d\n", journal->j_commit_request, journal->j_commit_sequence); + journal->j_running_transaction->t_requested = jiffies; wake_up(&journal->j_wait_commit); return 1; } else if (!tid_geq(journal->j_commit_request, target)) @@ -898,13 +899,18 @@ 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 up to %u blocks\n", - s->stats->ts_tid, - s->journal->j_max_transaction_buffers); + seq_printf(seq, "%lu transactions (%lu requested), " + "each up to %u blocks\n", + s->stats->ts_tid, s->stats->ts_requested, + 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->run.rs_wait / s->stats->ts_tid)); + seq_printf(seq, " %ums request delay\n", + (s->stats->ts_requested == 0) ? 0 : + jiffies_to_msecs(s->stats->run.rs_request_delay / + s->stats->ts_requested)); seq_printf(seq, " %ums running transaction\n", jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); seq_printf(seq, " %ums transaction was being locked\n", diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index df9f29760efa..735609e2d636 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -100,6 +100,7 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) journal->j_running_transaction = transaction; transaction->t_max_wait = 0; transaction->t_start = jiffies; + transaction->t_requested = 0; return transaction; } |