Commit 2d442920 authored by Ritesh Harjani's avatar Ritesh Harjani Committed by Theodore Ts'o
Browse files

jbd2: remove CONFIG_JBD2_DEBUG to update t_max_wait 



CONFIG_JBD2_DEBUG and jbd2_journal_enable_debug knobs were added in
update_t_max_wait(), since earlier it used to take a spinlock for
updating t_max_wait, which could cause a bottleneck while starting a
txn (start_this_handle()).

Since in previous patch, we have killed t_handle_lock completely, we
could get rid of this debug config and knob to let t_max_wait be
updated by default again.

Signed-off-by: default avatarRitesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/ad7319a601fd501079310747ce87d908e0944763.1644992076.git.riteshh@linux.ibm.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent f7f497cb

fs/jbd2/transaction.c

+3 −4
Original line number Diff line number Diff line
@@ -141,20 +141,19 @@ static void jbd2_get_transaction(journal_t *journal, 
 * t_max_wait is carefully updated here with use of atomic compare exchange.

 * Note that there could be multiplre threads trying to do this simultaneously

 * hence using cmpxchg to avoid any use of locks in this case.

 * With this t_max_wait can be updated w/o enabling jbd2_journal_enable_debug.

 */

static inline void update_t_max_wait(transaction_t *transaction,

				     unsigned long ts)

{

#ifdef CONFIG_JBD2_DEBUG

	unsigned long oldts, newts;

	if (jbd2_journal_enable_debug &&

	    time_after(transaction->t_start, ts)) {



	if (time_after(transaction->t_start, ts)) {

		newts = jbd2_time_diff(ts, transaction->t_start);

		oldts = READ_ONCE(transaction->t_max_wait);

		while (oldts < newts)

			oldts = cmpxchg(&transaction->t_max_wait, oldts, newts);

	}

#endif

}



/*