Re: 2.5.48-mm1

From: William Lee Irwin III (wli@holomorphy.com)
Date: Thu Nov 21 2002 - 20:08:53 EST


On Thu, Nov 21, 2002 at 04:04:25PM -0500, Bill Davidsen wrote:
> This is purely a performance decision. If you want to avoid bad latency on
> reads then you have to throttle writes. The loop_thread will make the
> system just as slow as a user application writing the same number of
> pages.
> If you want io scheduling you will deliberately slow writes to let reads
> happen in reasonable time. And vice-versa I imagine, although I don't
> think I've seen that case.

Not entirely so. This is just a scheduling decision that has to
discriminate between blocking and nonblocking requests and prevent
starvation of the blocking requests. Write throttling is an
oversimplification that functions poorly.

Bill
-
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/



This archive was generated by hypermail 2b29 : Sat Nov 23 2002 - 22:00:39 EST