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/[email protected]
Signed-off-by: Jia Guo <[email protected]>
Reviewed-by: Jun Piao <[email protected]>
Reviewed-by: Yiwen Jiang <[email protected]>
Acked-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions