On Tue, Nov 21 2000, kumon@flab.fujitsu.co.jp wrote:
> > Believe it or not, but this is intentional. In that regard, the
> > function name is a misnomer -- call it i/o scheduler instead :-)
>
> I never believe it intentional. If it is true, the current kernel
> will be suffered from a kind of DOS attack. Yes, actually I'm a
> victim of it.
The problem is caused by the too high sequence numbers in stock
kernel, as I said. Plus, the sequence decrementing doesn't take
request/buffer size into account. So the starvation _is_ limited,
the limit is just too high.
> By Running ZD's ServerBench, not only the performance down, but my
> machine blocks all commands execution including /bin/ps, /bin/ls... ,
> and those are not ^C able unless the benchmark is stopped. Those
> commands are read from disks but the requests are wating at the end of
> I/O queue, those won't be executed.
If performance is down, then that problem is most likely elsewhere.
I/O limited benchmarking typically thrives on lots of request
latency -- with that comes better throughput for individual threads.
> Anyway, I'll try your patch.
Thanks
-- * Jens Axboe <axboe@suse.de> * SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Nov 23 2000 - 21:00:20 EST