diff options
| -rw-r--r-- | fs/jbd2/transaction.c | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index d95cc9d0401..f3479d6e0a8 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -82,6 +82,32 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) */ /* + * Update transiaction's maximum wait time, if debugging is enabled. + * + * In order for t_max_wait to be reliable, it must be protected by a + * lock. But doing so will mean that start_this_handle() can not be + * run in parallel on SMP systems, which limits our scalability. So + * unless debugging is enabled, we no longer update t_max_wait, which + * means that maximum wait time reported by the jbd2_run_stats + * tracepoint will always be zero. + */ +static inline void update_t_max_wait(transaction_t *transaction) +{ +#ifdef CONFIG_JBD2_DEBUG + unsigned long ts = jiffies; + + if (jbd2_journal_enable_debug && + time_after(transaction->t_start, ts)) { + ts = jbd2_time_diff(ts, transaction->t_start); + spin_lock(&transaction->t_handle_lock); + if (ts > transaction->t_max_wait) + transaction->t_max_wait = ts; + spin_unlock(&transaction->t_handle_lock); + } +#endif +} + +/* * start_this_handle: Given a handle, deal with any locking or stalling * needed to make sure that there is enough journal space for the handle * to begin. Attach the handle to a transaction and set up the @@ -95,7 +121,6 @@ static int start_this_handle(journal_t *journal, handle_t *handle, int needed; int nblocks = handle->h_buffer_credits; transaction_t *new_transaction = NULL; - unsigned long ts = jiffies; if (nblocks > journal->j_max_transaction_buffers) { printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", @@ -241,25 +266,8 @@ repeat: /* OK, account for the buffers that this operation expects to * use and add the handle to the running transaction. - * - * In order for t_max_wait to be reliable, it must be - * protected by a lock. But doing so will mean that - * start_this_handle() can not be run in parallel on SMP - * systems, which limits our scalability. So we only enable - * it when debugging is enabled. We may want to use a - * separate flag, eventually, so we can enable this - * independently of debugging. */ -#ifdef CONFIG_JBD2_DEBUG - if (jbd2_journal_enable_debug && - time_after(transaction->t_start, ts)) { - ts = jbd2_time_diff(ts, transaction->t_start); - spin_lock(&transaction->t_handle_lock); - if (ts > transaction->t_max_wait) - transaction->t_max_wait = ts; - spin_unlock(&transaction->t_handle_lock); - } -#endif + update_t_max_wait(transaction); handle->h_transaction = transaction; atomic_inc(&transaction->t_updates); atomic_inc(&transaction->t_handle_count); |