[mvapich-discuss] regestration cache limits in mvapich 0.9.7

[Sayantan Sur]

Hello Pasha,

>
>
> >Actually the check #3 can be removed, you have the same check in #6 ,
> >is not it?
>
> What do you think about this point (it is from previous email in this 
> thread) ?

Sorry I missed this question in your last email.

This extra check has some benefit. The registration logic registers the 
user buffer and then tries to insert the "VMA region" in the AVL tree. 
This is where the other check is made to make sure the total number of 
registered pages doesn't exceed the user defined value. If in case a 
SINGLE registration is exceeding the user defined limit, this branch 
will avoid the entire buffer being registered and subsequently 
de-registered due to the user limit being exceeded. This extra condition 
is executed only when new buffers are being registered (nothing compared 
to the huge registration overhead etc.) and definitely not in the 
critical path.

Thanks,
Sayantan.

-- 
http://www.cse.ohio-state.edu/~surs