Commit 874b1ef0 authored by Jia Guo's avatar Jia Guo Committed by Linus Torvalds
Browse files

ocfs2: optimize the reading of heartbeat data 

Reading heartbeat data from lowest node rather than from zero, in cases
where the node is not defined from zero, can reduce the number of sectors
read.

Here is a simple test data obtained with 'iostat -dmx dm-5 2', with
two nodes in the cluster, node number 10, 20, respectively.

Before optimization:
Device:         rrqm/s   wrqm/s     r/s     w/s    rMB/s    wMB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
dm-5              0.00     0.00    0.50    0.50     0.01     0.00    11.00     0.00    1.00    1.00    1.00   1.50   0.15

After the optimization:
Device:         rrqm/s   wrqm/s     r/s     w/s    rMB/s    wMB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
dm-5              0.00     0.00    0.50    0.50     0.00     0.00     6.00     0.00    0.50    1.00    0.00   0.50   0.05

Link: http://lkml.kernel.org/r/99fe4988-69ac-3615-a218-3042fe6fbe72@huawei.com


Signed-off-by: default avatarJia Guo <guojia12@huawei.com>
Reviewed-by: default avatarJun Piao <piaojun@huawei.com>
Reviewed-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
Acked-by: default avatarJoseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a9ee3a63

fs/ocfs2/cluster/heartbeat.c

+12 −5
Original line number Diff line number Diff line
@@ -582,9 +582,10 @@ bail: 
}



static int o2hb_read_slots(struct o2hb_region *reg,

			   unsigned int begin_slot,

			   unsigned int max_slots)

{

	unsigned int current_slot=0;

	unsigned int current_slot = begin_slot;

	int status;

	struct o2hb_bio_wait_ctxt wc;

	struct bio *bio;
@@ -1093,9 +1094,14 @@ static int o2hb_highest_node(unsigned long *nodes, int numbits) 
	return find_last_bit(nodes, numbits);

}



static int o2hb_lowest_node(unsigned long *nodes, int numbits)

{

	return find_first_bit(nodes, numbits);

}



static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)

{

	int i, ret, highest_node;

	int i, ret, highest_node, lowest_node;

	int membership_change = 0, own_slot_ok = 0;

	unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];

	unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
@@ -1120,7 +1126,8 @@ static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) 
	}



	highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);

	if (highest_node >= O2NM_MAX_NODES) {

	lowest_node = o2hb_lowest_node(configured_nodes, O2NM_MAX_NODES);

	if (highest_node >= O2NM_MAX_NODES || lowest_node >= O2NM_MAX_NODES) {

		mlog(ML_NOTICE, "o2hb: No configured nodes found!\n");

		ret = -EINVAL;

		goto bail;
@@ -1130,7 +1137,7 @@ static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) 
	 * yet. Of course, if the node definitions have holes in them

	 * then we're reading an empty slot anyway... Consider this

	 * best-effort. */

	ret = o2hb_read_slots(reg, highest_node + 1);

	ret = o2hb_read_slots(reg, lowest_node, highest_node + 1);

	if (ret < 0) {

		mlog_errno(ret);

		goto bail;
@@ -1801,7 +1808,7 @@ static int o2hb_populate_slot_data(struct o2hb_region *reg) 
	struct o2hb_disk_slot *slot;

	struct o2hb_disk_heartbeat_block *hb_block;



	ret = o2hb_read_slots(reg, reg->hr_blocks);

	ret = o2hb_read_slots(reg, 0, reg->hr_blocks);

	if (ret)

		goto out;

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