diff options
| -rw-r--r-- | fs/xfs/libxfs/xfs_defer.c | 2 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 18 | ||||
| -rw-r--r-- | fs/xfs/xfs_trans_ail.c | 116 | ||||
| -rw-r--r-- | fs/xfs/xfs_trans_priv.h | 11 |
4 files changed, 80 insertions, 67 deletions
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c index e2c8308d518b..40021849b42f 100644 --- a/fs/xfs/libxfs/xfs_defer.c +++ b/fs/xfs/libxfs/xfs_defer.c @@ -558,7 +558,7 @@ xfs_defer_relog( * the log threshold once per call. */ if (threshold_lsn == NULLCOMMITLSN) { - threshold_lsn = xfs_ail_push_target(log->l_ailp); + threshold_lsn = xfs_ail_get_push_target(log->l_ailp); if (threshold_lsn == NULLCOMMITLSN) break; } diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 0482b11965e2..971871b84d84 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -625,6 +625,24 @@ xlog_wait( int xlog_wait_on_iclog(struct xlog_in_core *iclog) __releases(iclog->ic_log->l_icloglock); +/* Calculate the distance between two LSNs in bytes */ +static inline uint64_t +xlog_lsn_sub( + struct xlog *log, + xfs_lsn_t high, + xfs_lsn_t low) +{ + uint32_t hi_cycle = CYCLE_LSN(high); + uint32_t hi_block = BLOCK_LSN(high); + uint32_t lo_cycle = CYCLE_LSN(low); + uint32_t lo_block = BLOCK_LSN(low); + + if (hi_cycle == lo_cycle) + return BBTOB(hi_block - lo_block); + ASSERT((hi_cycle == lo_cycle + 1) || xlog_is_shutdown(log)); + return (uint64_t)log->l_logsize - BBTOB(lo_block - hi_block); +} + /* * The LSN is valid so long as it is behind the current LSN. If it isn't, this * means that the next log record that includes this metadata could have a diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index a6b6fca1d138..26d4d9b3e357 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -398,51 +398,69 @@ xfsaild_push_item( /* * Compute the LSN that we'd need to push the log tail towards in order to have * at least 25% of the log space free. If the log free space already meets this - * threshold, this function returns NULLCOMMITLSN. + * threshold, this function returns the lowest LSN in the AIL to slowly keep + * writeback ticking over and the tail of the log moving forward. */ -xfs_lsn_t -__xfs_ail_push_target( +static xfs_lsn_t +xfs_ail_calc_push_target( struct xfs_ail *ailp) { - struct xlog *log = ailp->ail_log; - xfs_lsn_t threshold_lsn = 0; - xfs_lsn_t last_sync_lsn; - int free_blocks; - int free_bytes; - int threshold_block; - int threshold_cycle; - int free_threshold; - - free_bytes = xlog_space_left(log, &log->l_reserve_head.grant); - free_blocks = BTOBBT(free_bytes); + struct xlog *log = ailp->ail_log; + struct xfs_log_item *lip; + xfs_lsn_t target_lsn; + xfs_lsn_t max_lsn; + xfs_lsn_t min_lsn; + int32_t free_bytes; + uint32_t target_block; + uint32_t target_cycle; + + lockdep_assert_held(&ailp->ail_lock); + + lip = xfs_ail_max(ailp); + if (!lip) + return NULLCOMMITLSN; + + max_lsn = lip->li_lsn; + min_lsn = __xfs_ail_min_lsn(ailp); /* - * The threshold for the minimum number of free blocks is one quarter of - * the entire log space. + * If we are supposed to push all the items in the AIL, we want to push + * to the current head. We then clear the push flag so that we don't + * keep pushing newly queued items beyond where the push all command was + * run. If the push waiter wants to empty the ail, it should queue + * itself on the ail_empty wait queue. */ - free_threshold = log->l_logBBsize >> 2; - if (free_blocks >= free_threshold) - return NULLCOMMITLSN; + if (test_and_clear_bit(XFS_AIL_OPSTATE_PUSH_ALL, &ailp->ail_opstate)) + return max_lsn; + + /* If someone wants the AIL empty, keep pushing everything we have. */ + if (waitqueue_active(&ailp->ail_empty)) + return max_lsn; - xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle, - &threshold_block); - threshold_block += free_threshold; - if (threshold_block >= log->l_logBBsize) { - threshold_block -= log->l_logBBsize; - threshold_cycle += 1; - } - threshold_lsn = xlog_assign_lsn(threshold_cycle, - threshold_block); /* - * Don't pass in an lsn greater than the lsn of the last - * log record known to be on disk. Use a snapshot of the last sync lsn - * so that it doesn't change between the compare and the set. + * Background pushing - attempt to keep 25% of the log free and if we + * have that much free retain the existing target. */ - last_sync_lsn = atomic64_read(&log->l_last_sync_lsn); - if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0) - threshold_lsn = last_sync_lsn; + free_bytes = log->l_logsize - xlog_lsn_sub(log, max_lsn, min_lsn); + if (free_bytes >= log->l_logsize >> 2) + return ailp->ail_target; + + target_cycle = CYCLE_LSN(min_lsn); + target_block = BLOCK_LSN(min_lsn) + (log->l_logBBsize >> 2); + if (target_block >= log->l_logBBsize) { + target_block -= log->l_logBBsize; + target_cycle += 1; + } + target_lsn = xlog_assign_lsn(target_cycle, target_block); + + /* Cap the target to the highest LSN known to be in the AIL. */ + if (XFS_LSN_CMP(target_lsn, max_lsn) > 0) + return max_lsn; - return threshold_lsn; + /* If the existing target is higher than the new target, keep it. */ + if (XFS_LSN_CMP(ailp->ail_target, target_lsn) >= 0) + return ailp->ail_target; + return target_lsn; } static long @@ -453,7 +471,6 @@ xfsaild_push( struct xfs_ail_cursor cur; struct xfs_log_item *lip; xfs_lsn_t lsn; - xfs_lsn_t target = NULLCOMMITLSN; long tout; int stuck = 0; int flushing = 0; @@ -478,25 +495,8 @@ xfsaild_push( } spin_lock(&ailp->ail_lock); - - /* - * If we have a sync push waiter, we always have to push till the AIL is - * empty. Update the target to point to the end of the AIL so that - * capture updates that occur after the sync push waiter has gone to - * sleep. - */ - if (test_bit(XFS_AIL_OPSTATE_PUSH_ALL, &ailp->ail_opstate) || - waitqueue_active(&ailp->ail_empty)) { - lip = xfs_ail_max(ailp); - if (lip) - target = lip->li_lsn; - else - clear_bit(XFS_AIL_OPSTATE_PUSH_ALL, &ailp->ail_opstate); - } else { - target = __xfs_ail_push_target(ailp); - } - - if (target == NULLCOMMITLSN) + WRITE_ONCE(ailp->ail_target, xfs_ail_calc_push_target(ailp)); + if (ailp->ail_target == NULLCOMMITLSN) goto out_done; /* we're done if the AIL is empty or our push has reached the end */ @@ -506,10 +506,10 @@ xfsaild_push( XFS_STATS_INC(mp, xs_push_ail); - ASSERT(target != NULLCOMMITLSN); + ASSERT(ailp->ail_target != NULLCOMMITLSN); lsn = lip->li_lsn; - while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { + while ((XFS_LSN_CMP(lip->li_lsn, ailp->ail_target) <= 0)) { int lock_result; /* @@ -595,7 +595,7 @@ out_done: if (xfs_buf_delwri_submit_nowait(&ailp->ail_buf_list)) ailp->ail_log_flush++; - if (!count || XFS_LSN_CMP(lsn, target) >= 0) { + if (!count || XFS_LSN_CMP(lsn, ailp->ail_target) >= 0) { /* * We reached the target or the AIL is empty, so wait a bit * longer for I/O to complete and remove pushed items from the diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h index 9a131e7fae94..60b4707c3a65 100644 --- a/fs/xfs/xfs_trans_priv.h +++ b/fs/xfs/xfs_trans_priv.h @@ -59,6 +59,7 @@ struct xfs_ail { unsigned long ail_opstate; struct list_head ail_buf_list; wait_queue_head_t ail_empty; + xfs_lsn_t ail_target; }; /* Push all items out of the AIL immediately. */ @@ -111,15 +112,9 @@ static inline void xfs_ail_push_all(struct xfs_ail *ailp) xfs_ail_push(ailp); } -xfs_lsn_t __xfs_ail_push_target(struct xfs_ail *ailp); -static inline xfs_lsn_t xfs_ail_push_target(struct xfs_ail *ailp) +static inline xfs_lsn_t xfs_ail_get_push_target(struct xfs_ail *ailp) { - xfs_lsn_t lsn; - - spin_lock(&ailp->ail_lock); - lsn = __xfs_ail_push_target(ailp); - spin_unlock(&ailp->ail_lock); - return lsn; + return READ_ONCE(ailp->ail_target); } void xfs_ail_push_all_sync(struct xfs_ail *ailp); |