On Tue 06-06-23 21:59:25, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
>
> journal_clean_one_cp_list() and journal_shrink_one_cp_list() are almost
> the same, so merge them into journal_shrink_one_cp_list(), remove the
> nr_to_scan parameter, always scan and try to free the whole checkpoint
> list.
>
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/jbd2/checkpoint.c | 75 +++++++++----------------------------
> include/trace/events/jbd2.h | 12 ++----
> 2 files changed, 21 insertions(+), 66 deletions(-)
>
> diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
> index 55d6efdbea64..b94f847960c2 100644
> --- a/fs/jbd2/checkpoint.c
> +++ b/fs/jbd2/checkpoint.c
> @@ -347,50 +347,10 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
>
> /* Checkpoint list management */
>
> -/*
> - * journal_clean_one_cp_list
> - *
> - * Find all the written-back checkpoint buffers in the given list and
> - * release them. If 'destroy' is set, clean all buffers unconditionally.
> - *
> - * Called with j_list_lock held.
> - * Returns 1 if we freed the transaction, 0 otherwise.
> - */
> -static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
> -{
> - struct journal_head *last_jh;
> - struct journal_head *next_jh = jh;
> -
> - if (!jh)
> - return 0;
> -
> - last_jh = jh->b_cpprev;
> - do {
> - jh = next_jh;
> - next_jh = jh->b_cpnext;
> -
> - if (!destroy && __cp_buffer_busy(jh))
> - return 0;
> -
> - if (__jbd2_journal_remove_checkpoint(jh))
> - return 1;
> - /*
> - * This function only frees up some memory
> - * if possible so we dont have an obligation
> - * to finish processing. Bail out if preemption
> - * requested:
> - */
> - if (need_resched())
> - return 0;
> - } while (jh != last_jh);
> -
> - return 0;
> -}
> -
> /*
> * journal_shrink_one_cp_list
> *
> - * Find 'nr_to_scan' written-back checkpoint buffers in the given list
> + * Find all the written-back checkpoint buffers in the given list
> * and try to release them. If the whole transaction is released, set
> * the 'released' parameter. Return the number of released checkpointed
> * buffers.
> @@ -398,15 +358,15 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
> * Called with j_list_lock held.
> */
> static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
> - unsigned long *nr_to_scan,
> - bool *released)
> + bool destroy, bool *released)
> {
> struct journal_head *last_jh;
> struct journal_head *next_jh = jh;
> unsigned long nr_freed = 0;
> int ret;
>
> - if (!jh || *nr_to_scan == 0)
> + *released = false;
> + if (!jh)
> return 0;
>
> last_jh = jh->b_cpprev;
> @@ -414,8 +374,7 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
> jh = next_jh;
> next_jh = jh->b_cpnext;
>
> - (*nr_to_scan)--;
> - if (__cp_buffer_busy(jh))
> + if (!destroy && __cp_buffer_busy(jh))
> continue;
>
> nr_freed++;
> @@ -427,7 +386,7 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
>
> if (need_resched())
> break;
> - } while (jh != last_jh && *nr_to_scan);
> + } while (jh != last_jh);
>
> return nr_freed;
> }
> @@ -445,11 +404,11 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
> unsigned long *nr_to_scan)
> {
> transaction_t *transaction, *last_transaction, *next_transaction;
> - bool released;
> + bool __maybe_unused released;
> tid_t first_tid = 0, last_tid = 0, next_tid = 0;
> tid_t tid = 0;
> unsigned long nr_freed = 0;
> - unsigned long nr_scanned = *nr_to_scan;
> + unsigned long freed;
>
> again:
> spin_lock(&journal->j_list_lock);
> @@ -478,10 +437,11 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
> transaction = next_transaction;
> next_transaction = transaction->t_cpnext;
> tid = transaction->t_tid;
> - released = false;
>
> - nr_freed += journal_shrink_one_cp_list(transaction->t_checkpoint_list,
> - nr_to_scan, &released);
> + freed = journal_shrink_one_cp_list(transaction->t_checkpoint_list,
> + false, &released);
> + nr_freed += freed;
> + (*nr_to_scan) -= min(*nr_to_scan, freed);
> if (*nr_to_scan == 0)
> break;
> if (need_resched() || spin_needbreak(&journal->j_list_lock))
> @@ -502,9 +462,8 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
> if (*nr_to_scan && next_tid)
> goto again;
> out:
> - nr_scanned -= *nr_to_scan;
> trace_jbd2_shrink_checkpoint_list(journal, first_tid, tid, last_tid,
> - nr_freed, nr_scanned, next_tid);
> + nr_freed, next_tid);
>
> return nr_freed;
> }
> @@ -520,7 +479,7 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
> void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
> {
> transaction_t *transaction, *last_transaction, *next_transaction;
> - int ret;
> + bool released;
>
> transaction = journal->j_checkpoint_transactions;
> if (!transaction)
> @@ -531,8 +490,8 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
> do {
> transaction = next_transaction;
> next_transaction = transaction->t_cpnext;
> - ret = journal_clean_one_cp_list(transaction->t_checkpoint_list,
> - destroy);
> + journal_shrink_one_cp_list(transaction->t_checkpoint_list,
> + destroy, &released);
> /*
> * This function only frees up some memory if possible so we
> * dont have an obligation to finish processing. Bail out if
> @@ -545,7 +504,7 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
> * avoids pointless scanning of transactions which still
> * weren't checkpointed.
> */
> - if (!ret)
> + if (!released)
> return;
> } while (transaction != last_transaction);
> }
> diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h
> index 8f5ee380d309..5646ae15a957 100644
> --- a/include/trace/events/jbd2.h
> +++ b/include/trace/events/jbd2.h
> @@ -462,11 +462,9 @@ TRACE_EVENT(jbd2_shrink_scan_exit,
> TRACE_EVENT(jbd2_shrink_checkpoint_list,
>
> TP_PROTO(journal_t *journal, tid_t first_tid, tid_t tid, tid_t last_tid,
> - unsigned long nr_freed, unsigned long nr_scanned,
> - tid_t next_tid),
> + unsigned long nr_freed, tid_t next_tid),
>
> - TP_ARGS(journal, first_tid, tid, last_tid, nr_freed,
> - nr_scanned, next_tid),
> + TP_ARGS(journal, first_tid, tid, last_tid, nr_freed, next_tid),
>
> TP_STRUCT__entry(
> __field(dev_t, dev)
> @@ -474,7 +472,6 @@ TRACE_EVENT(jbd2_shrink_checkpoint_list,
> __field(tid_t, tid)
> __field(tid_t, last_tid)
> __field(unsigned long, nr_freed)
> - __field(unsigned long, nr_scanned)
> __field(tid_t, next_tid)
> ),
>
> @@ -484,15 +481,14 @@ TRACE_EVENT(jbd2_shrink_checkpoint_list,
> __entry->tid = tid;
> __entry->last_tid = last_tid;
> __entry->nr_freed = nr_freed;
> - __entry->nr_scanned = nr_scanned;
> __entry->next_tid = next_tid;
> ),
>
> TP_printk("dev %d,%d shrink transaction %u-%u(%u) freed %lu "
> - "scanned %lu next transaction %u",
> + "next transaction %u",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> __entry->first_tid, __entry->tid, __entry->last_tid,
> - __entry->nr_freed, __entry->nr_scanned, __entry->next_tid)
> + __entry->nr_freed, __entry->next_tid)
> );
>
> #endif /* _TRACE_JBD2_H */
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
