Hi!
I have a wish for Linux 3.x and blkio cgroup subsystem:
Allow to specify any device like: blkio.throttle.read_bps_device = "*:* 41943040"
Why: With multipathing being effective, you can't predict the device number your device will have in advance (I'm talking about "/etc/cgconfig.conf").
Example:
# multipath -ll |grep dm-
CBW_DB_FATA-E2 (3600508b4001085dd0001100003800000) dm-10 HP,HSV200
CBW_CI-E2 (3600508b4001085dd00011000040c0000) dm-12 HP,HSV200
CBW_DB_FATA-E1 (3600508b4001085e30000f00001810000) dm-18 HP,HSV200
CBW_CI-E1 (3600508b4001085e30000f00001f60000) dm-19 HP,HSV200
DP_FileLib-E2 (3600508b4001085dd0001100004be0000) dm-16 HP,HSV200
CBW_DB_Exe-E2 (3600508b4001085dd00011000037b0000) dm-11 HP,HSV200
CBW_DB_Exe-E1 (3600508b4001085e30000f000017e0000) dm-17 HP,HSV200
DP_DB_10k-E2 (3600508b4001085dd0001100004480000) dm-15 HP,HSV200
CBW_DB_BTD-E2 (3600508b4001085dd0001100005ad0000) dm-14 HP,HSV200
DP_DB_10k-E1 (3600508b4001085e30000f00002460000) dm-20 HP,HSV200
CBW_DB_10k-E2 (3600508b4001085dd0001100005a50000) dm-9 HP,HSV200
CBW_DB_10k-E1 (3600508b4001085e30000f000035f0000) dm-13 HP,HSV200
The code is in blkio_policy_parse_and_set() of blk-cgroup.c.
Regards,
Ulrich