cvs commit: src/sys/dev/bce if_bcereg.h

Scott Long scottl at
Wed Apr 26 06:24:40 UTC 2006

Matthew Jacob wrote:
>> And actually, it's 100% impossible to do a transfer larger than 2^32 on
>> PCI Express due to the protocol requiring that a transfer not cross a
>> 4GB boundary.
> You could still have a device that you program with > 2^32 and it'll 
> take care of the segment issues.
>> So, I think that we are pretty safe with this typedef for
>> the next 5-10 years.
> Nope. I give it 3 years max.
>>  Of course, I'll be honored when Linus calls me a
>> moron for this 7 years from now =-)
>> Scott

Oh, I'm sure that you could contrive a silly device today to prove your
point.  But really, what are you going to do other than DMA completely
randomly-associated memory pages that just happen to neighbor each
other?  It's not like the kernel or any user process can own more than
4GB of memory on i386+PAE.


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