diff options
author | Theodore Ts'o <tytso@mit.edu> | 2010-08-03 21:35:12 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2010-08-03 21:35:12 -0400 |
commit | a931da6ac9331a6c80dd91c199105806f2336188 (patch) | |
tree | 2d4ea766def9a98d21c2379f41e796b0e57ccd6b /fs/jbd2/journal.c | |
parent | a51dca9cd3bb4ec5a05bfb6feabf024a5c808a37 (diff) | |
download | lwn-a931da6ac9331a6c80dd91c199105806f2336188.tar.gz lwn-a931da6ac9331a6c80dd91c199105806f2336188.zip |
jbd2: Change j_state_lock to be a rwlock_t
Lockstat reports have shown that j_state_lock is a major source of
lock contention, especially on systems with more than 4 CPU cores. So
change it to be a read/write spinlock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/journal.c')
-rw-r--r-- | fs/jbd2/journal.c | 94 |
1 files changed, 46 insertions, 48 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index a79d3345b55a..e7bf0fd9cec7 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -142,7 +142,7 @@ static int kjournald2(void *arg) /* * And now, wait forever for commit wakeup events. */ - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); loop: if (journal->j_flags & JBD2_UNMOUNT) @@ -153,10 +153,10 @@ loop: if (journal->j_commit_sequence != journal->j_commit_request) { jbd_debug(1, "OK, requests differ\n"); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); del_timer_sync(&journal->j_commit_timer); jbd2_journal_commit_transaction(journal); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); goto loop; } @@ -168,9 +168,9 @@ loop: * be already stopped. */ jbd_debug(1, "Now suspending kjournald2\n"); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); refrigerator(); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); } else { /* * We assume on resume that commits are already there, @@ -190,9 +190,9 @@ loop: if (journal->j_flags & JBD2_UNMOUNT) should_sleep = 0; if (should_sleep) { - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); schedule(); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); } finish_wait(&journal->j_wait_commit, &wait); } @@ -210,7 +210,7 @@ loop: goto loop; end_loop: - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); del_timer_sync(&journal->j_commit_timer); journal->j_task = NULL; wake_up(&journal->j_wait_done_commit); @@ -233,16 +233,16 @@ static int jbd2_journal_start_thread(journal_t *journal) static void journal_kill_thread(journal_t *journal) { - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); journal->j_flags |= JBD2_UNMOUNT; while (journal->j_task) { wake_up(&journal->j_wait_commit); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); wait_event(journal->j_wait_done_commit, journal->j_task == NULL); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); } - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); } /* @@ -452,7 +452,7 @@ int __jbd2_log_space_left(journal_t *journal) { int left = journal->j_free; - assert_spin_locked(&journal->j_state_lock); + /* assert_spin_locked(&journal->j_state_lock); */ /* * Be pessimistic here about the number of those free blocks which @@ -497,9 +497,9 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid) { int ret; - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); ret = __jbd2_log_start_commit(journal, tid); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); return ret; } @@ -518,7 +518,7 @@ int jbd2_journal_force_commit_nested(journal_t *journal) transaction_t *transaction = NULL; tid_t tid; - spin_lock(&journal->j_state_lock); + read_lock(&journal->j_state_lock); if (journal->j_running_transaction && !current->journal_info) { transaction = journal->j_running_transaction; __jbd2_log_start_commit(journal, transaction->t_tid); @@ -526,12 +526,12 @@ int jbd2_journal_force_commit_nested(journal_t *journal) transaction = journal->j_committing_transaction; if (!transaction) { - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); return 0; /* Nothing to retry */ } tid = transaction->t_tid; - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); jbd2_log_wait_commit(journal, tid); return 1; } @@ -545,7 +545,7 @@ int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) { int ret = 0; - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); if (journal->j_running_transaction) { tid_t tid = journal->j_running_transaction->t_tid; @@ -564,7 +564,7 @@ int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) *ptid = journal->j_committing_transaction->t_tid; ret = 1; } - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); return ret; } @@ -576,26 +576,24 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid) { int err = 0; + read_lock(&journal->j_state_lock); #ifdef CONFIG_JBD2_DEBUG - spin_lock(&journal->j_state_lock); if (!tid_geq(journal->j_commit_request, tid)) { printk(KERN_EMERG "%s: error: j_commit_request=%d, tid=%d\n", __func__, journal->j_commit_request, tid); } - spin_unlock(&journal->j_state_lock); #endif - spin_lock(&journal->j_state_lock); while (tid_gt(tid, journal->j_commit_sequence)) { jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", tid, journal->j_commit_sequence); wake_up(&journal->j_wait_commit); - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); wait_event(journal->j_wait_done_commit, !tid_gt(tid, journal->j_commit_sequence)); - spin_lock(&journal->j_state_lock); + read_lock(&journal->j_state_lock); } - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); if (unlikely(is_journal_aborted(journal))) { printk(KERN_EMERG "journal commit I/O error\n"); @@ -612,7 +610,7 @@ int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) { unsigned long blocknr; - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); J_ASSERT(journal->j_free > 1); blocknr = journal->j_head; @@ -620,7 +618,7 @@ int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) journal->j_free--; if (journal->j_head == journal->j_last) journal->j_head = journal->j_first; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); return jbd2_journal_bmap(journal, blocknr, retp); } @@ -840,7 +838,7 @@ static journal_t * journal_init_common (void) mutex_init(&journal->j_checkpoint_mutex); spin_lock_init(&journal->j_revoke_lock); spin_lock_init(&journal->j_list_lock); - spin_lock_init(&journal->j_state_lock); + rwlock_init(&journal->j_state_lock); journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); journal->j_min_batch_time = 0; @@ -1106,14 +1104,14 @@ void jbd2_journal_update_superblock(journal_t *journal, int wait) set_buffer_uptodate(bh); } - spin_lock(&journal->j_state_lock); + read_lock(&journal->j_state_lock); jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", journal->j_tail, journal->j_tail_sequence, journal->j_errno); sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); sb->s_start = cpu_to_be32(journal->j_tail); sb->s_errno = cpu_to_be32(journal->j_errno); - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); BUFFER_TRACE(bh, "marking dirty"); mark_buffer_dirty(bh); @@ -1134,12 +1132,12 @@ out: * any future commit will have to be careful to update the * superblock again to re-record the true start of the log. */ - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); if (sb->s_start) journal->j_flags &= ~JBD2_FLUSHED; else journal->j_flags |= JBD2_FLUSHED; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); } /* @@ -1551,7 +1549,7 @@ int jbd2_journal_flush(journal_t *journal) transaction_t *transaction = NULL; unsigned long old_tail; - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); /* Force everything buffered to the log... */ if (journal->j_running_transaction) { @@ -1564,10 +1562,10 @@ int jbd2_journal_flush(journal_t *journal) if (transaction) { tid_t tid = transaction->t_tid; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); jbd2_log_wait_commit(journal, tid); } else { - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); } /* ...and flush everything in the log out to disk. */ @@ -1591,12 +1589,12 @@ int jbd2_journal_flush(journal_t *journal) * the magic code for a fully-recovered superblock. Any future * commits of data to the journal will restore the current * s_start value. */ - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); old_tail = journal->j_tail; journal->j_tail = 0; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); jbd2_journal_update_superblock(journal, 1); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); journal->j_tail = old_tail; J_ASSERT(!journal->j_running_transaction); @@ -1604,7 +1602,7 @@ int jbd2_journal_flush(journal_t *journal) J_ASSERT(!journal->j_checkpoint_transactions); J_ASSERT(journal->j_head == journal->j_tail); J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); return 0; } @@ -1668,12 +1666,12 @@ void __jbd2_journal_abort_hard(journal_t *journal) printk(KERN_ERR "Aborting journal on device %s.\n", journal->j_devname); - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); journal->j_flags |= JBD2_ABORT; transaction = journal->j_running_transaction; if (transaction) __jbd2_log_start_commit(journal, transaction->t_tid); - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); } /* Soft abort: record the abort error status in the journal superblock, @@ -1758,12 +1756,12 @@ int jbd2_journal_errno(journal_t *journal) { int err; - spin_lock(&journal->j_state_lock); + read_lock(&journal->j_state_lock); if (journal->j_flags & JBD2_ABORT) err = -EROFS; else err = journal->j_errno; - spin_unlock(&journal->j_state_lock); + read_unlock(&journal->j_state_lock); return err; } @@ -1778,12 +1776,12 @@ int jbd2_journal_clear_err(journal_t *journal) { int err = 0; - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); if (journal->j_flags & JBD2_ABORT) err = -EROFS; else journal->j_errno = 0; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); return err; } @@ -1796,10 +1794,10 @@ int jbd2_journal_clear_err(journal_t *journal) */ void jbd2_journal_ack_err(journal_t *journal) { - spin_lock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); if (journal->j_errno) journal->j_flags |= JBD2_ACK_ERR; - spin_unlock(&journal->j_state_lock); + write_unlock(&journal->j_state_lock); } int jbd2_journal_blocks_per_page(struct inode *inode) |