Commit 00574da1 authored by Zhi Yong Wu's avatar Zhi Yong Wu Committed by Ben Myers
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xfs: introduce object readahead to log recovery 



  It can take a long time to run log recovery operation because it is
single threaded and is bound by read latency. We can find that it took
most of the time to wait for the read IO to occur, so if one object
readahead is introduced to log recovery, it will obviously reduce the
log recovery time.

Log recovery time stat:

          w/o this patch        w/ this patch

real:        0m15.023s             0m7.802s
user:        0m0.001s              0m0.001s
sys:         0m0.246s              0m0.107s

Signed-off-by: default avatarZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: default avatarBen Myers <bpm@sgi.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent 8d1d4083

fs/xfs/xfs_log_recover.c

+152 −7
Original line number Diff line number Diff line
@@ -3119,6 +3119,106 @@ xlog_recover_free_trans( 
	kmem_free(trans);

}



STATIC void

xlog_recover_buffer_ra_pass2(

	struct xlog                     *log,

	struct xlog_recover_item        *item)

{

	struct xfs_buf_log_format	*buf_f = item->ri_buf[0].i_addr;

	struct xfs_mount		*mp = log->l_mp;



	if (xlog_check_buffer_cancelled(log, buf_f->blf_blkno,

			buf_f->blf_len, buf_f->blf_flags)) {

		return;

	}



	xfs_buf_readahead(mp->m_ddev_targp, buf_f->blf_blkno,

				buf_f->blf_len, NULL);

}



STATIC void

xlog_recover_inode_ra_pass2(

	struct xlog                     *log,

	struct xlog_recover_item        *item)

{

	struct xfs_inode_log_format	ilf_buf;

	struct xfs_inode_log_format	*ilfp;

	struct xfs_mount		*mp = log->l_mp;

	int			error;



	if (item->ri_buf[0].i_len == sizeof(struct xfs_inode_log_format)) {

		ilfp = item->ri_buf[0].i_addr;

	} else {

		ilfp = &ilf_buf;

		memset(ilfp, 0, sizeof(*ilfp));

		error = xfs_inode_item_format_convert(&item->ri_buf[0], ilfp);

		if (error)

			return;

	}



	if (xlog_check_buffer_cancelled(log, ilfp->ilf_blkno, ilfp->ilf_len, 0))

		return;



	xfs_buf_readahead(mp->m_ddev_targp, ilfp->ilf_blkno,

				ilfp->ilf_len, &xfs_inode_buf_ops);

}



STATIC void

xlog_recover_dquot_ra_pass2(

	struct xlog			*log,

	struct xlog_recover_item	*item)

{

	struct xfs_mount	*mp = log->l_mp;

	struct xfs_disk_dquot	*recddq;

	struct xfs_dq_logformat	*dq_f;

	uint			type;





	if (mp->m_qflags == 0)

		return;



	recddq = item->ri_buf[1].i_addr;

	if (recddq == NULL)

		return;

	if (item->ri_buf[1].i_len < sizeof(struct xfs_disk_dquot))

		return;



	type = recddq->d_flags & (XFS_DQ_USER | XFS_DQ_PROJ | XFS_DQ_GROUP);

	ASSERT(type);

	if (log->l_quotaoffs_flag & type)

		return;



	dq_f = item->ri_buf[0].i_addr;

	ASSERT(dq_f);

	ASSERT(dq_f->qlf_len == 1);



	xfs_buf_readahead(mp->m_ddev_targp, dq_f->qlf_blkno,

				dq_f->qlf_len, NULL);

}



STATIC void

xlog_recover_ra_pass2(

	struct xlog			*log,

	struct xlog_recover_item	*item)

{

	switch (ITEM_TYPE(item)) {

	case XFS_LI_BUF:

		xlog_recover_buffer_ra_pass2(log, item);

		break;

	case XFS_LI_INODE:

		xlog_recover_inode_ra_pass2(log, item);

		break;

	case XFS_LI_DQUOT:

		xlog_recover_dquot_ra_pass2(log, item);

		break;

	case XFS_LI_EFI:

	case XFS_LI_EFD:

	case XFS_LI_QUOTAOFF:

	default:

		break;

	}

}



STATIC int

xlog_recover_commit_pass1(

	struct xlog			*log,
@@ -3180,6 +3280,26 @@ xlog_recover_commit_pass2( 
	}

}



STATIC int

xlog_recover_items_pass2(

	struct xlog                     *log,

	struct xlog_recover             *trans,

	struct list_head                *buffer_list,

	struct list_head                *item_list)

{

	struct xlog_recover_item	*item;

	int				error = 0;



	list_for_each_entry(item, item_list, ri_list) {

		error = xlog_recover_commit_pass2(log, trans,

					  buffer_list, item);

		if (error)

			return error;

	}



	return error;

}



/*

 * Perform the transaction.

 *
@@ -3192,9 +3312,16 @@ xlog_recover_commit_trans( 
	struct xlog_recover	*trans,

	int			pass)

{

	int			error = 0, error2;

	xlog_recover_item_t	*item;

	int				error = 0;

	int				error2;

	int				items_queued = 0;

	struct xlog_recover_item	*item;

	struct xlog_recover_item	*next;

	LIST_HEAD			(buffer_list);

	LIST_HEAD			(ra_list);

	LIST_HEAD			(done_list);



	#define XLOG_RECOVER_COMMIT_QUEUE_MAX 100



	hlist_del(&trans->r_list);
@@ -3202,14 +3329,22 @@ xlog_recover_commit_trans( 
	if (error)

		return error;



	list_for_each_entry(item, &trans->r_itemq, ri_list) {

	list_for_each_entry_safe(item, next, &trans->r_itemq, ri_list) {

		switch (pass) {

		case XLOG_RECOVER_PASS1:

			error = xlog_recover_commit_pass1(log, trans, item);

			break;

		case XLOG_RECOVER_PASS2:

			error = xlog_recover_commit_pass2(log, trans,

							  &buffer_list, item);

			xlog_recover_ra_pass2(log, item);

			list_move_tail(&item->ri_list, &ra_list);

			items_queued++;

			if (items_queued >= XLOG_RECOVER_COMMIT_QUEUE_MAX) {

				error = xlog_recover_items_pass2(log, trans,

						&buffer_list, &ra_list);

				list_splice_tail_init(&ra_list, &done_list);

				items_queued = 0;

			}



			break;

		default:

			ASSERT(0);
@@ -3219,9 +3354,19 @@ xlog_recover_commit_trans( 
			goto out;

	}



out:

	if (!list_empty(&ra_list)) {

		if (!error)

			error = xlog_recover_items_pass2(log, trans,

					&buffer_list, &ra_list);

		list_splice_tail_init(&ra_list, &done_list);

	}



	if (!list_empty(&done_list))

		list_splice_init(&done_list, &trans->r_itemq);



	xlog_recover_free_trans(trans);



out:

	error2 = xfs_buf_delwri_submit(&buffer_list);

	return error ? error : error2;

}

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