[PATCH 3.2 27/94] ext4: disable synchronous transaction batching if max_batch_time==0
From: Ben Hutchings <hidden>
Date: 2014-08-04 16:55:33
Also in:
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3.2.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Sandeen <redacted> commit 5dd214248f94d430d70e9230bda72f2654ac88a8 upstream. The mount manpage says of the max_batch_time option, This optimization can be turned off entirely by setting max_batch_time to 0. But the code doesn't do that. So fix the code to do that. Signed-off-by: Eric Sandeen <redacted> Signed-off-by: Theodore Ts'o <tytso@mit.edu> [bwh: Backported to 3.2: option parsing looks different] Signed-off-by: Ben Hutchings <redacted> --- fs/ext4/super.c | 2 -- fs/jbd2/transaction.c | 5 ++++- 2 files changed, 4 insertions(+), 3 deletions(-)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c@@ -1663,8 +1663,6 @@ static int parse_options(char *options, 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: --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c
@@ -1388,9 +1388,12 @@ int jbd2_journal_stop(handle_t *handle) * 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 for joiners in that case. + * + * Setting max_batch_time to 0 disables this completely. */ pid = current->pid; - if (handle->h_sync && journal->j_last_sync_writer != pid) { + if (handle->h_sync && journal->j_last_sync_writer != pid && + journal->j_max_batch_time) { u64 commit_time, trans_time; journal->j_last_sync_writer = pid;