From 874b1ef0ef5117c071f431fdebbf388eccbcc1f2 Mon Sep 17 00:00:00 2001 From: Jia Guo Date: Fri, 28 Dec 2018 00:32:35 -0800 Subject: [PATCH] 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: Jia Guo Reviewed-by: Jun Piao Reviewed-by: Yiwen Jiang Acked-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/cluster/heartbeat.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 9b2ed62dd638..f3c20b279eb2 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/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 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;