From: Jia Guo <guojia12@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Jia Guo <guojia12@xxxxxxxxxx> Reviewed-by: Jun Piao <piaojun@xxxxxxxxxx> Reviewed-by: Yiwen Jiang <jiangyiwen@xxxxxxxxxx> Acked-by: Joseph Qi <jiangqi903@xxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Changwei Ge <ge.changwei@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/fs/ocfs2/cluster/heartbeat.c~ocfs2-optimize-the-reading-of-heartbeat-data +++ a/fs/ocfs2/cluster/heartbeat.c @@ -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 lo 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 } 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 * 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(struc 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; _
