Peter Zijlstra wrote: > On Sat, 2008-01-12 at 16:27 +0530, Balbir Singh wrote: >> * Peter Zijlstra <[EMAIL PROTECTED]> [2008-01-12 10:46:37]: >> >>> On Fri, 2008-01-11 at 23:57 -0500, [EMAIL PROTECTED] wrote: >>>> On Fri, 11 Jan 2008 17:32:49 +0100, Andrea Righi said: >>>> >>>>> The interesting feature is that it allows to set a priority for each >>>>> process container, but AFAIK it doesn't allow to "partition" the >>>>> bandwidth between different containers (that would be a nice feature >>>>> IMHO). For example it would be great to be able to define per-container >>>>> limits, like assign 10MB/s for processes in container A, 30MB/s to >>>>> container B, 20MB/s to container C, etc. >>>> Has anybody considered allocating based on *seeks* rather than bytes moved, >>>> or counting seeks as "virtual bytes" for the purposes of accounting (if the >>>> disk can do 50mbytes/sec, and a seek takes 5millisecs, then count it as >>>> 100K >>>> of data)? >>> I was considering a time scheduler, you can fill your time slot with >>> seeks or data, it might be what CFQ does, but I've never even read the >>> code. >>> >> So far the definition of I/O bandwidth has been w.r.t time. Not all IO >> devices have sectors; I'd prefer bytes over a period of time. > > Doing a time based one would only require knowing the (avg) delay of > seeks, whereas doing a bytes based one would also require knowing the > (avg) speed of the device. > > That is, if you're also interested in providing a latency guarantee. > Because that'd force you to convert bytes to time again.
So, what about considering both bytes/sec and io-operations/sec? In this way we should be able to limit huge streams of data and seek storms (or any mix of them). Regarding CFQ, AFAIK it's only possible to configure an I/O priorty for a process, but there's no way for example to limit the bandwidth (or I/O operations/sec) for a particular user or group. -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/