Messages in this thread | | | Date | Mon, 16 Jul 2001 18:51:10 +0200 (CEST) | From | Martin Wilck <> |
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Hi,
sorry to join in so late in this thread, but I think I should bring the following to your attention:
Someone (David, I think) said that IA64 was handling 32-bit controllers fine. To my experience, that depends strongly on the drivers. At least for aic7xxx, it is not the case (I have documented the related crashes on the linux-ia64 mailing lists during the last two months). The driver is simply eating up buffer space in such vast amounts that it freezes the software IO-memory management even at very moderate load (you can use the "old" driver instead, but this doesn't look like a long-term solution).
After some discussion, Justin Gibbs announced that he'll implement 39-bit DMA addressing in the aic7xxx driver, and it appeared that this was pretty much the only viable solution to make the "new" aic7xxx driver work on IA64. I haven't looked at his new code yet, but I assume he's using the IA64 approach.
It is likely that this will happen for other drivers as well, especially those that need a lot of buffer space for good performance. Thus the IA-64 API will probably emerge as a matter-of-fact standard, and if something better is to replace it, I think it should be decided upon quickly, so that driver maintainers (and IA64) can adopt to it before everything has to be written (and debugged) twice.
Regards, Martin -- Martin Wilck <Martin.Wilck@fujitsu-siemens.com> FSC EP PS DS1, Paderborn Tel. +49 5251 8 15113
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