Messages in this thread |  | | | Subject | Re: IO performance problems in 2.4.19-pre5 when writing to DVD-RAM/ZIP/MO | | Date | Tue, 16 Apr 2002 17:09:17 +0100 (BST) | | From | Alan Cox <> |
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> > The problem is that writing to a DVD-RAM, ZIP or MO device almost > > totally blocks reading from a _different_ device. Here is some data.
Yes I saw this with M/O disks, thats one reason the -ac tree doesn't adopt all the ll_rw_blk/elevator changes from the vanilla tree.
> > DVD-RAM while reading from the (fast) 130GB HDD (benchmark 2) almost > > totally blocks the read process. Under 2.4.19-rc5, it takes 14 times
You'll see this on other things too. Large file creates seem to basically stall anything wanting swap
> > benchmarks 1-4, kernel 2.4.19-pre5 performed much worse than > > 2.4.18. The reason may be that the main throughput stems from the > > short moments where, for what reason whatsoever, read speed increases
Fairness, throughput, latency - pick any two..
> Right fix is different but not suitable for 2.4.
Curious - what do you think the right fix is ? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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