Messages in this thread | | | Subject | Re: DMA transfers in 2.5.67 | From | (Måns Rullgård) | Date | 16 Apr 2003 10:43:47 +0200 |
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Ivan Kokshaysky <ink@jurassic.park.msu.ru> writes:
> On Wed, Apr 16, 2003 at 12:09:00AM +0200, Måns Rullgård wrote: > > Btw, I just noticed that hard disk throughput is much lower with 2.5 > > than 2.4. With 2.4.21-pre5 I get ~40 MB/s, but with 2.5.67 the speed > > drops to 25-30 MB/s. Everything according to hdparm. Is it possible > > that DMA is generally slow for some reason? > > Possible reason is that in 2.4 we've forced reasonable latency timer > value for all PCI devices, while in 2.5 we haven't as yet.
Do you mean whatever causes this message (for a 3com NIC)?
PCI: Setting latency timer of device 00:05.0 to 64
Would that also explain why my hard disks are slow under 2.5? There is no corresponding message for the ide controller (htp374).
-- Måns Rullgård mru@users.sf.net - 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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