cvs commit: src/sys/alpha/alpha mem.c promcons.csrc/sys/alpha/tlsbsrc/sys/cam/scsi scsi_ch.c scsi_pass.c scsi_pt.c s

[Scott Long]

Poul-Henning Kamp wrote:
> In message <200402230945.42440.jhb at FreeBSD.org>, John Baldwin writes:
> 
>>On Saturday 21 February 2004 06:13 pm, Poul-Henning Kamp wrote:
>>
>>>In message <20040221161339.X52892 at pooker.samsco.home>, Scott Long writes:
>>>
>>>>>A grace period is not possible, that is why I have been so vocal
>>>>>with my heads-up messages to current for the last two weeks.
>>>>
>>>>What are the technical reasons for a grace period not being possible?
>>>
>>>The signflip on the GIANT flag.
>>
>>Which was arguably premature given the vast number of NEEDGIANT vs. NOGIANT 
>>case.  The MPSAFE flag for interrupts hasn't been flipped yet either for that 
>>reason.
> 
> 
> I thought the idea was to try to get the API's set up correctly before
> the RELENG_5 branch so that we do not make MFC'ing impossible a few
> months after the branchpoing like it happened for 3.x ?
> 
> At least that was part of my motivation for flipping the flag.
> 
> Another part is psychological:  I think we need to mark the spots
> that need work done rather than put congratulatory notices in dmesg
> for the little headway we've done.
> 
> And for both of these reasons I would advocate that MPSAFE gets flipped
> before the branch as well.
> 

I agree with these arguments.  However, I would have liked to have seen
a small grace period defined, especially since people are now bumping
into the consequences of this change and not knowing why.  I plan to do
this with the interrupt API change when it comes.

scott