> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:general- > [EMAIL PROTECTED] On Behalf Of Roland Dreier > Sent: Tuesday, February 12, 2008 2:42 PM > To: Christoph Lameter > Cc: Rik van Riel; [EMAIL PROTECTED]; Andrea Arcangeli; > [EMAIL PROTECTED]; [EMAIL PROTECTED]; linux- > [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; > [EMAIL PROTECTED]; Robin Holt; [EMAIL PROTECTED]; > Andrew Morton; [EMAIL PROTECTED] > Subject: Re: [ofa-general] Re: Demand paging for memory regions > > > > Chelsio's T3 HW doesn't support this. > > > Not so far I guess but it could be equipped with these features > right? > > I don't know anything about the T3 internals, but it's not clear that > you could do this without a new chip design in general. Lot's of RDMA > devices were designed expecting that when a packet arrives, the HW can > look up the bus address for a given memory region/offset and place the > packet immediately. It seems like a major change to be able to > generate a "page fault" interrupt when a page isn't present, or even > just wait to scatter some data until the host finishes updating page > tables when the HW needs the translation.
That is correct, not a change we can make for T3. We could, in theory, deal with changing mappings though. The change would need to be synchronized though: the VM would need to tell us which mapping were about to change and the driver would then need to disable DMA to/from it, do the change and resume DMA. > > - R. > > _______________________________________________ > general mailing list > [EMAIL PROTECTED] > http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib- > general -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
