Messages in this thread | | | Date | Tue, 12 Sep 2000 16:30:27 +0200 (CEST) | From | Andrea Arcangeli <> | Subject | Re: More on 2.2.18pre2aa2 |
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On Tue, 12 Sep 2000, Rik van Riel wrote:
>We can already set different figures for different drives.
Right.
>Would it really be more than 30 minutes of work to put in >a different request # limit for each drive that automatically >satisfies the latency specified by the user?
Note that if you know the transfer rate of each of your harddisk you can just almost emulate the "in function of time" behaviour by converting from "throughput" and "latency in function of time", to "latency in function of bh sized requests". (one userspace script could do that automatically for example using hdparm to first benchmark the throughput)
The reason I prefer working with "latency in function of bh sized requests" in kernel space is that I can just use one constant for most of the blockdevices. Using the same latency setting with the "in function of time approch" would be wrong instead (and you should gather some hardware info from the device before you are able to decide a good constant).
Andrea
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