Greetings... a patch I would like your comments on...

[Ivan Voras]

On 01/22/10 16:55, Randall Stewart wrote:

>> If I read the comment at filt_umtxattach() correctly, in the best case
>> you would need an extension to the kevent structure to add more fields
>> like data & udata (for passing values back and forth between userland
>> and kernel). I agree with this - it would be very convenient for some
>> future purposes (like file modification notification) if the kernel
>> filter could both accept and return a struct of data from/to the
>> userland.
>
> Yeah, more arguments inside the kevent would allow me to add the
> COND_CV_WAIT* where a lock and condition are passed
> in as well... But I was hesitant to add more than was already there
> since doing
> so would cause ABI ripples that I did not want to face.

Yes, this should be done carefully; just adding more "data" and "udata" 
fields will postpone the problem to when someone else needs one more 
field to make his idea working - a memory blob should probably be the 
way to go.

> I plan on committing this to head if I don't get strong "you idiot you
> did it wrong" comments ;-)

Hmmm, something just occured to me: why did you name the event / filter 
"EVFILT_KQUEUE"? Why not something like "EVFILT_UMTX" or "EVFLT_COND"?

You said you didn't make the actual connection to the userland pthead_* 
API yet - how did you test it?