Messages in this thread | | | Date | Mon, 21 Jan 2002 17:33:50 +0100 | From | Peter Wächtler <> | Subject | Re: [2.4.17/18pre] VM and swap - it's really unusable |
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yodaiken@fsmlabs.com schrieb: > > On Mon, Jan 21, 2002 at 05:05:01PM +0100, Daniel Phillips wrote: > > > I think of "benefit", perhaps naiively, in terms of something that can > > > be measured or demonstrated rather than just announced. > > > > But you see why asap scheduling improves latency/throughput *in theory*, > > Nope. And I don't even see a relationship between preemption and asap I/O > schedulding. What make you think that I/O threads won't be preempted by > other threads? >
I/O intensive threads block early voluntarily - while CPU hogs don't. Statistically there is a higher chance, that a CPU hog gets preempted instead of an IO bound (that gives up the CPU in some useconds anyway)
The next IO request is hitting the device "earlier" - instead of waiting for the next schedule() - that makes sense to me.
With this scenario the system CPU utilization gets "bigger" for the benefit of "faster" IO. OTOH, seti@home needs longer to run. - 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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