LU-16338 readahead: add stats for read-ahead page count
This patch adds the stats for read-ahead page count:
lctl get_param llite.*.read_ahead_stats
llite.lustre-
ffff938b7849d000.read_ahead_stats=
snapshot_time 4011.
320890492 secs.nsecs
start_time 0.
000000000 secs.nsecs
elapsed_time 4011.
320890492 secs.nsecs
hits 4 samples [pages]
misses 1 samples [pages]
zero_size_window 4 samples [pages]
failed_to_reach_end 1 samples [pages]
failed_to_fast_read 1 samples [pages]
readahead_pages 1 samples [pages] 255 255 255
Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: Iada06eb7d78ab28cfcc7167e49d25da252da4009
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49224
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Patrick Farrell <farr0186@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>