Messages in this thread |  | | Date | Wed, 13 Sep 2000 11:20:55 +0100 (BST) | From | Matthew Kirkwood <> | Subject | Re: (reiserfs) Re: More on 2.2.18pre2aa2 |
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On Tue, 12 Sep 2000, Rik van Riel wrote:
[ outrageous cc: list trimmed ]
> > >We simply keep track of how old the oldest request > > >in the queue is, and when that request is getting > > >too old (say 1/2 second), we /stop/ all the others > > > > Going in function of time is obviously wrong. A blockdevice can > > write 1 request every two seconds or 1 request every msecond. > > You can't assume anything in function of time _unless_ you have > > per harddisk timing informations into the kernel. > > Uhmmm, isn't the elevator about request /latency/ ? > > And if so, in what unit do you want to measure > latency if it isn't time?
Number of requests which get serviced between the insertion and completion of the request. Maybe scaled by the average i/o queue length[0].
Matthew.
[0] Insert obligatory "why oh why" on Linus' not taking SCT's sar/iostat patches.
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