Andrew Morton wrote:On Fri, 27 Jun 2008 00:36:46 +0200
Andrea Righi <righi.andrea@xxxxxxxxx> wrote:
Well it's functionally broken, isn't it? A physical disk has a fixedDoes all this code treat /dev/sda1 as a separate device from /dev/sda2?Yes, all the partitions are treated as separate devices with
If so, that would be broken.
(potentially) different limiting rules, but I don't understand why it
would be broken... dev_t has both minor and major numbers, so it would
be possible to select single partitions as well.
IO bandwidth and when the administrator wants to partition that
bandwidth amongst control groups he will need to consider the entire
device when doing so?
I mean, the whole point of this feature and of control groups as a
whole is isolation. But /dev/sda1 and /dev/sda2 are very much _not_
isolated. Whereas /dev/sda and /dev/sdb are (to a large degree)
isolated.
well... yes, sounds reasonable. In this case we could just ignore the
minor number and consider only major number as the key to identify a
specific block device (both for userspace<->kernel interface and when
accounting/throttling i/o requests).