[Ocfs2-devel] [PATCH] ocfs2: Optimize the reading of heartbeat data
Changwei Ge
ge.changwei at h3c.com
Tue Oct 23 18:21:33 PDT 2018
Hi Jia,
Your patch was not made properly and can't be applied to my work tree. :-(
Please check it.
Moreover, I *disagree* with your way trying to boost HB performance.
Actually, ocfs2 o2cb/heartbeat mechanism reads and writes region according slot number rather
than cluster node number.(Perhaps I missed something or your patch relies on your other patches)
And for slot assignment algorithm applied in ocfs2/mounting, the lowest slot number is always the first choice.
So your patch should not work...
Thanks,
Changwei
On 2018/10/23 20:33, Jia Guo wrote:
> 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
>
> Signed-off-by: Jia Guo <guojia12 at huawei.com>
> Reviewed-by: Jun Piao <piaojun at huawei.com>
> Reviewed-by: Yiwen Jiang <jiangyiwen at huawei.com>
> ---
> cluster/heartbeat.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/cluster/heartbeat.c b/cluster/heartbeat.c
> index 9b2ed62..a9cf984 100644
> --- a/cluster/heartbeat.c
> +++ b/cluster/heartbeat.c
> @@ -582,17 +582,18 @@ bail:
> }
>
> static int o2hb_read_slots(struct o2hb_region *reg,
> - unsigned int max_slots)
> + unsigned int min_slot,
> + unsigned int max_slot)
> {
> - unsigned int current_slot=0;
> + unsigned int current_slot = min_slot;
> int status;
> struct o2hb_bio_wait_ctxt wc;
> struct bio *bio;
>
> o2hb_bio_wait_init(&wc);
>
> - while(current_slot < max_slots) {
> - bio = o2hb_setup_one_bio(reg, &wc, ¤t_slot, max_slots,
> + while(current_slot < max_slot) {
> + bio = o2hb_setup_one_bio(reg, &wc, ¤t_slot, max_slot,
> REQ_OP_READ, 0);
> if (IS_ERR(bio)) {
> status = PTR_ERR(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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