Hi Jens,
I am testing current linux-block.git#wb-buf-throttle on top of Linux
v4.6-rc5 here on my Ubuntu/precise AMD64.
( Was installed as a WUBI "test" system - "testing" since April 2012 :-) .)
Here are some numbers:
# df -T | egrep 'sda|loop'
/dev/sda2 fuseblk 465546236 210981868 254564368 46% /host
/dev/loop0 ext4 17753424 15586612 1241936 93% /
# egrep 'sda|loop|ext4' /etc/fstab
/host/ubuntu/disks/root.disk / ext4
loop,errors=remount-ro 0 1
/host/ubuntu/disks/swap.disk none swap loop,sw
0 0
( Not sure why I cannot do a find on /sys/block/ .)
# find /sys/devices/ -name '*wb_stat*' | egrep 'loop0|sda'
/sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_stats
/sys/devices/virtual/block/loop0/queue/wb_stats
# find /sys/devices/ -name '*wb_lat*' | egrep 'loop0|sda'
/sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_lat_usec
/sys/devices/virtual/block/loop0/queue/wb_lat_usec
# cat /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_stats
/sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/queue/wb_lat_usec
background=8, normal=16, max=31, inflight=0, wait=0, bdp_wait=0
75000
# cat /sys/devices/virtual/block/loop0/queue/wb_stats
/sys/devices/virtual/block/loop0/queue/wb_lat_usec
background=16, normal=32, max=64, inflight=0, wait=0, bdp_wait=0
75000
Questions...
Planning a v5?
Will this go to Linux v4.7 or later?
How should someone test?
Documentation...
Can you add some more docs about getting infos (see above cat#s etc.)
below Documentation/ directory?
( Talking about the stuff you have embedded in the commit-messages. )