ext4: add fsync batch tuning knobs
Add new mount options, min_batch_time and max_batch_time, which
controls how long the jbd2 layer should wait for additional filesystem
operations to get batched with a synchronous write transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dc27d4c..da377f9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -705,10 +705,19 @@
#endif
if (!test_opt(sb, RESERVATION))
seq_puts(seq, ",noreservation");
- if (sbi->s_commit_interval) {
+ if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
seq_printf(seq, ",commit=%u",
(unsigned) (sbi->s_commit_interval / HZ));
}
+ if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
+ seq_printf(seq, ",min_batch_time=%u",
+ (unsigned) sbi->s_min_batch_time);
+ }
+ if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
+ seq_printf(seq, ",max_batch_time=%u",
+ (unsigned) sbi->s_min_batch_time);
+ }
+
/*
* We're changing the default of barrier mount option, so
* let's always display its mount state so it's clear what its
@@ -874,7 +883,8 @@
Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
- Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
+ Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
+ Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
Opt_journal_checksum, Opt_journal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
Opt_data_err_abort, Opt_data_err_ignore,
@@ -913,6 +923,8 @@
{Opt_nobh, "nobh"},
{Opt_bh, "bh"},
{Opt_commit, "commit=%u"},
+ {Opt_min_batch_time, "min_batch_time=%u"},
+ {Opt_max_batch_time, "max_batch_time=%u"},
{Opt_journal_update, "journal=update"},
{Opt_journal_inum, "journal=%u"},
{Opt_journal_dev, "journal_dev=%u"},
@@ -1131,6 +1143,22 @@
option = JBD2_DEFAULT_MAX_COMMIT_AGE;
sbi->s_commit_interval = HZ * option;
break;
+ case Opt_max_batch_time:
+ if (match_int(&args[0], &option))
+ return 0;
+ if (option < 0)
+ return 0;
+ if (option == 0)
+ option = EXT4_DEF_MAX_BATCH_TIME;
+ sbi->s_max_batch_time = option;
+ break;
+ case Opt_min_batch_time:
+ if (match_int(&args[0], &option))
+ return 0;
+ if (option < 0)
+ return 0;
+ sbi->s_min_batch_time = option;
+ break;
case Opt_data_journal:
data_opt = EXT4_MOUNT_JOURNAL_DATA;
goto datacheck;
@@ -1979,6 +2007,9 @@
sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+ sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
+ sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
+ sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
set_opt(sbi->s_mount_opt, RESERVATION);
set_opt(sbi->s_mount_opt, BARRIER);
@@ -2524,11 +2555,9 @@
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- if (sbi->s_commit_interval)
- journal->j_commit_interval = sbi->s_commit_interval;
- /* We could also set up an ext4-specific default for the commit
- * interval here, but for now we'll just fall back to the jbd
- * default. */
+ journal->j_commit_interval = sbi->s_commit_interval;
+ journal->j_min_batch_time = sbi->s_min_batch_time;
+ journal->j_max_batch_time = sbi->s_max_batch_time;
spin_lock(&journal->j_state_lock);
if (test_opt(sb, BARRIER))
@@ -3042,6 +3071,8 @@
old_opts.s_resuid = sbi->s_resuid;
old_opts.s_resgid = sbi->s_resgid;
old_opts.s_commit_interval = sbi->s_commit_interval;
+ old_opts.s_min_batch_time = sbi->s_min_batch_time;
+ old_opts.s_max_batch_time = sbi->s_max_batch_time;
#ifdef CONFIG_QUOTA
old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
for (i = 0; i < MAXQUOTAS; i++)
@@ -3178,6 +3209,8 @@
sbi->s_resuid = old_opts.s_resuid;
sbi->s_resgid = old_opts.s_resgid;
sbi->s_commit_interval = old_opts.s_commit_interval;
+ sbi->s_min_batch_time = old_opts.s_min_batch_time;
+ sbi->s_max_batch_time = old_opts.s_max_batch_time;
#ifdef CONFIG_QUOTA
sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
for (i = 0; i < MAXQUOTAS; i++) {