diff options
| -rw-r--r-- | fs/jbd/commit.c | 15 | ||||
| -rw-r--r-- | fs/jbd/transaction.c | 38 | ||||
| -rw-r--r-- | include/linux/jbd.h | 15 |
3 files changed, 63 insertions, 5 deletions
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 25719d902c51..3fbffb1ea714 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -306,6 +306,8 @@ void journal_commit_transaction(journal_t *journal) int flags; int err; unsigned long blocknr; + ktime_t start_time; + u64 commit_time; char *tagp = NULL; journal_header_t *header; journal_block_tag_t *tag = NULL; @@ -418,6 +420,7 @@ void journal_commit_transaction(journal_t *journal) commit_transaction->t_state = T_FLUSH; journal->j_committing_transaction = commit_transaction; journal->j_running_transaction = NULL; + start_time = ktime_get(); commit_transaction->t_log_start = journal->j_head; wake_up(&journal->j_wait_transaction_locked); spin_unlock(&journal->j_state_lock); @@ -913,6 +916,18 @@ restart_loop: J_ASSERT(commit_transaction == journal->j_committing_transaction); journal->j_commit_sequence = commit_transaction->t_tid; journal->j_committing_transaction = NULL; + commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); + + /* + * weight the commit time higher than the average time so we don't + * react too strongly to vast changes in commit time + */ + if (likely(journal->j_average_commit_time)) + journal->j_average_commit_time = (commit_time*3 + + journal->j_average_commit_time) / 4; + else + journal->j_average_commit_time = commit_time; + spin_unlock(&journal->j_state_lock); if (commit_transaction->t_checkpoint_list == NULL && diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index 60d4c32c8808..b51fbd4b2913 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -25,6 +25,7 @@ #include <linux/timer.h> #include <linux/mm.h> #include <linux/highmem.h> +#include <linux/hrtimer.h> static void __journal_temp_unlink_buffer(struct journal_head *jh); @@ -49,6 +50,7 @@ get_transaction(journal_t *journal, transaction_t *transaction) { transaction->t_journal = journal; transaction->t_state = T_RUNNING; + transaction->t_start_time = ktime_get(); transaction->t_tid = journal->j_transaction_sequence++; transaction->t_expires = jiffies + journal->j_commit_interval; spin_lock_init(&transaction->t_handle_lock); @@ -1370,7 +1372,7 @@ int journal_stop(handle_t *handle) { transaction_t *transaction = handle->h_transaction; journal_t *journal = transaction->t_journal; - int old_handle_count, err; + int err; pid_t pid; J_ASSERT(journal_current_handle() == handle); @@ -1399,6 +1401,17 @@ int journal_stop(handle_t *handle) * on IO anyway. Speeds up many-threaded, many-dir operations * by 30x or more... * + * We try and optimize the sleep time against what the underlying disk + * can do, instead of having a static sleep time. This is usefull for + * the case where our storage is so fast that it is more optimal to go + * ahead and force a flush and wait for the transaction to be committed + * than it is to wait for an arbitrary amount of time for new writers to + * join the transaction. We acheive this by measuring how long it takes + * to commit a transaction, and compare it with how long this + * transaction has been running, and if run time < commit time then we + * sleep for the delta and commit. This greatly helps super fast disks + * that would see slowdowns as more threads started doing fsyncs. + * * But don't do this if this process was the most recent one to * perform a synchronous write. We do this to detect the case where a * single process is doing a stream of sync writes. No point in waiting @@ -1406,11 +1419,26 @@ int journal_stop(handle_t *handle) */ pid = current->pid; if (handle->h_sync && journal->j_last_sync_writer != pid) { + u64 commit_time, trans_time; + journal->j_last_sync_writer = pid; - do { - old_handle_count = transaction->t_handle_count; - schedule_timeout_uninterruptible(1); - } while (old_handle_count != transaction->t_handle_count); + + spin_lock(&journal->j_state_lock); + commit_time = journal->j_average_commit_time; + spin_unlock(&journal->j_state_lock); + + trans_time = ktime_to_ns(ktime_sub(ktime_get(), + transaction->t_start_time)); + + commit_time = min_t(u64, commit_time, + 1000*jiffies_to_usecs(1)); + + if (trans_time < commit_time) { + ktime_t expires = ktime_add_ns(ktime_get(), + commit_time); + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); + } } current->journal_info = NULL; diff --git a/include/linux/jbd.h b/include/linux/jbd.h index 346e2b80be7d..6384b19efe64 100644 --- a/include/linux/jbd.h +++ b/include/linux/jbd.h @@ -543,6 +543,11 @@ struct transaction_s unsigned long t_expires; /* + * When this transaction started, in nanoseconds [no locking] + */ + ktime_t t_start_time; + + /* * How many handles used this transaction? [t_handle_lock] */ int t_handle_count; @@ -798,9 +803,19 @@ struct journal_s struct buffer_head **j_wbuf; int j_wbufsize; + /* + * this is the pid of the last person to run a synchronous operation + * through the journal. + */ pid_t j_last_sync_writer; /* + * the average amount of time in nanoseconds it takes to commit a + * transaction to the disk. [j_state_lock] + */ + u64 j_average_commit_time; + + /* * An opaque pointer to fs-private information. ext3 puts its * superblock pointer here */ |