Paul Menage wrote: > On Jan 23, 2008 8:48 AM, Andrea Righi <[EMAIL PROTECTED]> wrote: >>> 1. Implementation of soft limits (limit on contention of resource) >>> gets harder >> Why? do you mean implementing a grace time when the soft-limit is >> exceeded? this could be done in cgroup_nl_throttle() introducing 3 >> additional attributes to struct netlimit (i.e. hard_limit, >> last_time_exceeded grace_time) and perform something like: >> ... >> if ((current_rate > hard_limit) || >> time_after(jiffies, last_time_exceeded + grace_time)) >> schedule_timeout(sleep); >> ... > > He's talking about cases where we want the behaviour to be > work-conserving, whilst still offering guarantees in the event of > contention. e.g. cgroups A and B each get a 20% guarantee on the TX > path if they need it, but anyone can use any otherwise-idle bandwidth. > (This is relatively straightforward to set up from userspace with the > standard Linux traffic control tools).
OK. >> Yes, the integration with iptables (as Paul said), and traffic shaping >> rules would be absolutely the right way(tm) in perspective. I was just >> proposing a possible simple API to implement the limiting stuff. > > But this issue (traffic control for cgroups) is too complex to be > described by a simple API. Any simple API you choose to try to > describe the limiting directly will be insufficient for a good number > of the potential users. Better to just provide a (very simple) API to > hook into the existing (complex) traffic control API and leave the > tricky stuff to userspace, where anyone can construct arbitrarily > complex queueing schemes with a shell script and a few calls to "tc". > > Paul > OK, thanks for the clarifications. -Andrea -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
